Having spent the majority of my life in electronics ( Radio Rentals, Colourvision, Chandos to name a few) and having attained two degrees I still revert to basics when fault finding. This is a skill that never leaves you, don't forget that just because you find one fault doesn't mean there are not others! Keep up the good work, we need more younger people in the industry to combat the throw away society we have built.
Andrew Doherty I totally agree. Radio Rentals eh? I actually thought about 10 years ago, that these skills would die out with the last of my generation. Fortunately thanks to the internet, increased awareness of environmental issues (we all understand now that we have to change our ways) and a lot of good guys out there on forums and elsewhere sharing old school knowledge, I'm now sure that is not the case. It feels like there is a whole renaissance going on with younger people getting interested in repair now 😁
Andrew ,,,, ( MY man ) ... This is an extraordinary time. Interactive communications for the people ! Thank you for adding to the mindset of repair, not junk, the gear that got us here. We need a massive influx of workers to undo all the waste that is overwhelming the planet. Your comment is very helpful to me and other readers. I have gear that I refuse to let go ... hopefully I'll bring back to the second life that is well deserved. Thanks again Sir.
This is a great electronics repair refresher. Just last week I was able to repair a $5k KitchenAid refrigerator's main board with a broken fuse caused by a shorted rectifier. I had no access to circuit diagram nor does the manufacturer provides it. The board is $650 brand new with a 3 month wait and $500 of factory repair labor, and I was able to fix it with $3 in parts and knowledge in electronics repair.
For anyone interested... Handy Andy took the PCB back to the client yesterday afternoon, with strict instructions to check for a short circuit heater element before trying it. This morning before I got up out of bed, I was just thinking about that negative 5V regulator (79M05) and what it may have been doing. I often think about stuff like that, I guess I'm electronically minded through and through LOL. So anyway, here is my take on it, though I no longer have the PCB to check this. I think the 79M05 is connected like this: The PIC18 needs a positive 5V supply and yet the Vcc (power in) of the PIC18 micro-controller will be connected to 12V from the transformer and bridge rectifier. The 79M05 minus 5V regulator then holds the 'ground' pin of the PIC18 at exactly 5V less (more negative) than the +12V supply. This means the PIC18 has a +5V supply but it is referenced from +12V. Now why? Well there are two relays on the PCB with 12V coils and the PIC needs to switch them on or off. There are two little transistors and diodes near the relays (I checked the diodes). I think the transistors are probably P Channel MOSFETS and switch power to the relay coils, so the P Channel MOSFET connects from +12V, to the relay coil positive end, and the other end of the coil connects to ground. This means the MOSFET can supply the 12V the relay needs to turn on. To switch the MOSFET off, the PIC18 has to put 12V on the Gate and to switch it on is has to put *less than* 12V on the gate. Because the circuit designer connected the +5V Vcc pin of the PIC18 to +12V it can easily send +12V or less to the P-MOSFET gate and therefore switch the 12V relays with the minimum of components. Simples ehh? PS the diodes by the MOSFETS will be to stop back EMF when the relay coils turns off 😉
@Mr Guru Bear in mind I am not 100% sure that the circuit works this way, it's just me picturing in my mind why it would have a 7905 negative regulator on a positive 12V supply. And the above is my best guess, would you go along with this being the likely circuit design for the reason I thought (ease of driving 12V relay coils). I don't suppose it is any more or less reliable than a 7805 or even a buck converter, as you mention. 🙂
Good fault diagnosis but something odd / bizarre. You can use a negative supply on a PIC to invert signal states but if you put 12V on Vdd and -5V on Vss (or reference any of the GPIO pins to +5V with -5V on Vss) then it's bye-bye PIC. I suspect the -5V is being used for something else as well, because they could have easily used a positive 5V regulator to power the PIC and then the PIC drives n-channel MOSFETs to turn on the 12V relays.
@@ralphj4012 See my pinned comment for my detailed thoughts on this. I believe the PIC Vcc is connected to 12V and PIC Vdd is connected to the output of the 79M05 to set the voltage at that point to Vcc less 5V which would be +7V with reference to the negative end of the bridge rectifier. So the PIC still has a stable +5V supply between Vdd And Vcc, just not with reference to the negative end of the bridge. Although the 7905 is a negative 5V regulator, it doesn't to have output -5V with respect to ground, it could be -5V with respect to +12V 🙂
@@LearnElectronicsRepair Indeed, but onnecting the common and output of a linear regulator together to create a voltage subtractor is odd (unless they were intending originally to create a current source circuit then chaged their mind). Maybe they had a load of 79M05's to get rid of.
26:00 Italian here! Let me translate some words for you: Macina -> Grinder Pompa -> Pump (pretty self explanatory) Motore -> Motor Sonda Flusso -> Flow Probe By the way, great video! Very easy to follow even for a beginner like me, I actually guessed some things right as you were going along the board
Sounds like you worked for a similar firm as I did: Deritend. A board like this should take less than 10 minutes to diagnose. My tips from 35 years in electronics fault finding like this: 1> Follow the current, follow the voltage. High energy is a vulnerability. 2> Follow the heat, look for burns & heat toasting. 3> Ignore the intelligence (micro). If it is damaged you can't get it anyway because it contains firmware. 4> Resistors fail by increasing value, almost never by reducing, all the way to open. In circuit they can ONLY reduce in value. If it reads less than the marked value it is likely OK. 5> Electrolytic capacitors always fall in value, they cannot rise. They don't like heat. The ones near heat sinks will fail. usually they bulge if bad. If all else fails, swap them all out anyway. 6> Measure each component, concentrating on the low hanging fruit. Mark it with a dot from a marker pen if good, move on. The last check of a suspect component should be desoldered to confirm it is bad. 7> Mechanical devices like switches & relays are unreliable. 8> Connectors are reliable but their solder mount pins are not because of mechanical stresses. 9> Heavy things which are soldered are vulnerable for mechanical reasons. 10> Nearly every fault will have a visual clue. 11> Closely, inspect solder side with magnifier around through hole pins. 12> If you have two boards you can VI trace compare.
My brother is an Electrician and asked me how can you fix a board if you do not have the schematic for it. This is how to do it just like you did. I make my own schematic and my brother was impressed that i can do that as I have never taken any course on electronics.
You just took the card and drew a schematic for it. This is very impressive. This is much easier to do with consumer electronics. I totally agree with that. The power circuits are much more easier to track because they are simpler. Most of them are low power electronics and they don't need lots of components or control circuits like one would find in a computer part. I love your videos because you don't go like "This shows this symptom so this component is faulty." You start by doing a visual inspection and then check the connections. After this, you draw the circuit and think about what might go wrong and why it might go wrong. You don't just teach how to repair something. You try to teach it with the basics. Even though this makes the videos long, every second is worth it. You used to upload PSU videos and I hope I will see some more of them in the future. Great job.
@@LearnElectronicsRepair Yay. My switching power supply let out the magic smoke when it overheated. I replaced the transistors, but the protection circuit is still activated and I'm stumped. I left board electronics in the 80s and admit, I've lost it since. Stupid dark side (I.T.).
Good that you're making these in detail videos. Most of the laptop or macbook repair channels have very poor understanding of electronics. Thank you, this will be very helpful.
As a latecomer to hobbyist electronics, I'm dumbfounded why RUclips have never presented your channel before. Your diagnostics explanation is second to none. Great video. Thanks. I will subscribe, & check out some of your other efforts.
You Sir, just bought yourself another subscriber. I'm a qualified electrical Eng that used to work in office automation repair here in New Zealand, been a long time since though so your channel is now integral to my brushing up on PCB faultfinding! for that I sincerely thank you :) brilliant delivery and diagnostic skills that make a seasoned man green with envy!
wait up a while, electrical and electronics are different animals here. Electronics tends to be any voltage but mainly below 5v electrical tends to be specific to 240v , 120v in some countries, but generally known as main voltage. Electronics would normally cover anything up to and including a mains input...... I have a great story on that where I covered my arse well with 3 or 4 colleagues and 2 group managers when a display unit went up in a cosmic blue smokey haze, like I warned them it could, and was assured it did not matter as no one else would ever need to mess with the guts. . Not sure what I liked more, probably having all the emails where I pre warned them and they responded it was not an issue and they decided to escalate it to their group manager and my group manager . Forwarding those lies they told was a choice they made when questioning my honesty I guess, . they all new I kept very good notes on everything, covering my arse was never an exception.
Great video, I am a self employed coffee machine service engineer UK, have been repairing commercial coffee machines for 35 years (make a good living) I suspect it was the heating element that blew which takes out the triac (very common) I replace many triacs BTB16 (16 amp) I also always check the opto coupler/isolator as well. I studied industrial electronics for four years in the 80s/90s so this helps with repairing some of the problems on the boards.
It's always good to watch an experienced technician/engineer work. The short rant at the end is very sound advice, i started learning about electronics out of pure curiosity and ended up coming up with a great side hustle just repairing small stuff, especially heaters, old game consoles and lcd monitors/tvs with basic knowledge of electronics.
Glad, you mentioned the possibility of short to ground. Because some people will miss this obviously dangerous situation. Thanks for fixing "anything."
Great video! I have been in electronics for 16 years now. It definitely comes down to the fundamentals. There may be different principles when dealing with different types of electronics (AC, DC, RF, etc.), but all electronic components are made of the same basic parts. Even if you know nothing about what you are looking at, you can learn a lot by looking up datasheets and just banging out various components with a DMM. Even better if you have a good, working example to compare measurements with!
Hi i really want to learn more about electronics and its fundamentals with practical knowledge any tip can I get because I am almost 16 year old, thanks for the help.
and occasionally luck? years ago, had one of the chinese TIG welders fry itself. never actually fixed it mostly as my lab pup at the time chose to chew the main board up... but i did figure out it was the h bridge driving the AC inverter section (AC/DC for ali) having issues. um, but as i cannabilised various other parts, i found a relay wasnt working... something involved in the HF start... fast forward to a month or two ago. plasma cutter, HF starts playing up. took me all of two seconds to diagnose... relay. default is to close when powered up, open once an arc is formed and current starts flowing... wasnt closing. see how long the replacement holds up. if it misbehaves i got the answer for it... mercury wetted!
I really appreciate you the way you explain this stuff. Showing how to troubleshoot a problem on a board you know very little about is one of, if not the biggest, missing links for many people trying to learn these skills. Watching you walk us through how to figure out what might be expected from the components on an unknown board 'in the real world' is what seems to be missing from many similar channels that I've seen. Looking at your list of videos, there's many more useful and educational videos to keep us busy for some time! Subscribed. Thank you.
Just stumbled across the channel, I started working in an electronics repair company repairing PCB's very much like these (domestic appliance) at 16. I'm now 30, diverted into automotive electronics and machine maintenance. Very nice to see some of my old trade on RUclips especially now knowing what I've learned over the years!
The way you explain all of what you're doing during the repair is just awesome. Another thing that made me happy about this video was seeing you took a few minutes to explain - or refresh - what is a TRIAC and how it works. It helped me a lot on understanding how it operates on the board and how it is related to the failure (short), since I've studied TRIACs some time ago. You've got a new subscriber.
This channel is a gem to find. Thank you, Sit for your generosity of knowledge and your dedication to being thorough with your efforts to share it. I truly appreciate your content.
What a lesson! Graduating as a mechanical engineer, now close to retirement have found the world of circuits and electronic components which is plenty of fun.
Could watch your videos all day mate , love to be a fly on the wall in there , id be like a sponge soaking up everything . Did my first ever laptop motherboard repair tonight , shorted cap on main power rail, laptops worth about 500 quid , its such a good feeling when your passion starts paying off
My background is in chemical engineering, but I dabble in some electronics repair / upgrade work for cars as a hobby! This video was very inspiring, I really appreciate it. It has given me some great food for thought for the next potential side hustle! Thank you :)
Thank you, I am a commercial coffee machine engineer in the Uk, The electronic fault finding nd repairs of boards. is currently not something I would consider. but after seeing your video plus ordering a triac tester. I hope to develop, not just for coffee machines. Im looking forward to learning more from your videos. Thank you.
A mate of mine is a gas fitter & he says it breakd his heart judy throwing boards away because his firm just send him in with replacement boards and he told me how much they cost even for just refurbished PCBs. After I picked myself up off the floor he rummaged in the van & I've now got a box full of faulty PCBs. So I'm after learning. Step by step is ideal for me (Asperger's lends itself to methodicalness) snd I've just discovered your channel. To say "I'm all ears!" would be a massive understatement. 😀☮️ Edit: Loved it! Absolutely blindin' mate! That Peak Atlas would pay for itself on day one. I was looking at a cheaper one but the Atlas didn't invent 2 resistors. That sort of thing could throw you off at the start. Ok, off to watch another. Subbed with a head full of ideas! Nice one! 😜
This was fascinating from a person who knows little to nothing about electronics. Love watching someone explore something in a way that explains a lot. Definitely subbed. I like the bit of advice toward the end as well.
Your “quick rant” is bang on Rich. It’s also about reducing electronics waste too. Now the coffee shop is back up and running with the machine and coffee drinkers can get their espresso fix too. Like you say too it’s easily worth $100 to them. And it would take less than an hour and hardly anything on the components and consumables. I just replaced a rectifier diode (in a bridge rectifier) on someone es welding machine wire motor. Part was less than £2 and he was over the moon as it is his favourite and best machine. Loving your videos Rich thanks. I have you playing in the background whilst I’m tinkering in the workshop.
You are master! I repair my Keyless Entry Receiver in my Jeep thank your clip! Electronics is black magic to me. but according to the methodical fault finding I checked the paths from the connector through the board one by one and found breaks! I soldered the corroded elements and it worked!
Great video! If everybody can have some tools and skills like yours, there would be so much lesser electronic waste in the world. Things are being manufactured at such a high speed and low cost, making repairing cost comparatively more expensive. Please keep the videos going!
I am a 19yo electromechanic from Argentina, I want to study Electronic engineering and your videos are of great help to me, I'm grateful that you are willing to share you knowledge and experience freely. Fault searching was always a roadblock for me, I understand, mostly, the circuits, but when I get in front of a circuit I have no idea where to start
This is absolutely amazing. I've been doing hobby soldering since I was a child. I've been watching teardowns and repair videos on RUclips for around 10 years as well, but aside from knowing that there's a thing called "the one wire circuit" and what a "capacitive dropper" circuit does, I've never felt any more equipped to actually diagnose a piece of electronics that's hit my desk. This was extremely enlightening, and is honestly getting me really excited to try and look back at my many many many "backlog" project boards. I'm definitely not anywhere near being able to truly diagnose things on your level, but this is one of the first times the process has actually made sense to me as a methodology. Thank you!
How nice to see, the way I was taught in a TV repair shop, even though you had a good idea where the fault was, the engineer who taught me insisted I went through the whole process, which became second nature, lovely video.
Excellent tutorial for people like myself who are not exactly professionals but like to investigate faults sometimes with good results. Thank you so much for sharing 🙏
Thanks a lot! As a mobility aid repair tech trained up in the field, but having no background in electronics, this is very useful getting my head around the deduction process in fault finding... I think I'll have a snoop around your channel to find more of these gems... Gr. P
Welcome aboard. Also take a look at Learn Electronics Repair Discord server, I think you will like it 😉 Learn Electronics Repair is now on Discord! Come and join the fun and let's fix stuff together, it's free and a nice place to be. discord.gg/vam6YC8vwU
What a fantastic repair from you Rich and what a great tutorial video! I still believe this is the best Electronics Repair channel on RUclips! Cheers, Darren
Good sir, thank you do much for your wisdom and knowledge. Being many years junior to you, i really appreciate your expertise in the field. As an EE, you definetly made me decide on starting electronics repair as a side job. All the good to you from Kazakhstan.
I’ve spent the majority of the past two nights watching RUclips videos on electronics repair and can say with certainty that I remain as confused as I was when I started watching last night.
Does anyone know how to find a self employed electronic repair person? Many factories would be interested in this skill and the service would be extremely useful!
yeah, it's true that learning how the basics, "pure electronic" side of things is a good, and even important step, not only can it be very useful , by learning how certain components are supposed to behave, eventually help you learn what certain part of a circuit is supposed to do witch can really help for testing and diagnosing it!!! haven't done tons of repairs myself so far, a few easy one here and there, so far i've mostly learned by using schematics and making my own stuff, like making diy shields to use with an arduino, or mod something. a lot of the components i use are all recycled from old stuff that either me or other peoples was gonna throw in the trash... in the beginning i've spent so many hours just tearing stuff apart to unsolder everything on the pcbs inside... XD but as my collection grew i'd often make research to find schematics i was able reproduce with what i had, for most off the chips i've pulled i would throw on a breadboard and study the datasheet, to then make and experiment with the most basic circuits needed to make them work! i still use a lot of those parts when experimenting to make something i want to build, but once i know it works and are ready to build the final permanent version, i do at least buy the most critical parts to make sure it last!!
sBeDs - you are doing exactly the sort of thing I was doing as a teenager, though it was all analog circuits then of course. If you want to not only learn, but master, electronics repair you are definitely going down the right track with what you are doing. Keep it up 🙂
@@LearnElectronicsRepair nice, and thanks!!! i've always loved to learn how things work, and how to make stuff myself, and electronics is definitely one of the subjects that interest me the most!!! And back at you, keep it up, your channel is already one of my favorite when it comes to electronics, the way you do repairs on camera and explain everything you're doing and why is just perfect!!!😝🙂
You mean to tell me everyone don’t start exactly like this. I bought my first computer just to take it apart. A week later I was a professional At bypassing WGA. And yes it paid the bills. People were gladly paying to remove watermarks. Some of those people still come to me religiously. Even though I quit working on computers around win 10 release.
I did the best repair to a Samsung TV I baked the processor board at 350F for 10 minutes. The 60 inch TV has been working for four years now. Has to be my all time best electronic repair.
My Brother in law is a Master Electrician. They had an amp at the shop that would not work. All three electricians gave up on it as could not figure out the problem. I figured it out in about 10 min. The main transformer had a thermal fuse that was blown. I unwound the coil by hand, replace the thermal fuse and then rewound the coil by hand. Fix it.
@@keylanoslokj1806 I pulled the end of the wire back around the center and kept doing that until I got to the thermal fuse. soldered in a new fuse then like a thread pushed it through the gap and rewound it. keep it as close to the same as when I unwound it. Reconnect the wire to the circuit. It is like threading a needle and threat but wrap it around the metal core. Do not take the metal core or laminate apart, just unwind the wire.
Brilliant - again! Can't remember whether I mentioned it but this week - thanks to your videos - I fixed an old function generator. The fault was not one of the thirty or so solid state components but two short circuit tantalum capacitors shorting the positive and negative rails to earth.
Thanks for the video. Really enjoyed the signal flow, explaining the parts in further detail, how they work, and then finding the fault and testing. Look forward to the next one!
I got my start with TV repair. Can't get service manuals and schematics for most of them now, and it's just not worth reverse engineering and tracing out circuits on a TV which can be replaced for $200. I don't do it anymore, but I learned a lot from it and the skills apply to all electronics.
I have learned a lot from your videos. I always wanted to dabble into the world of electronics as I was always interested in repairing circuit boards and other board appliances myself. I tip my hat to you, sir
I've recently been repairing my infant daughters toy electronics. Extremely simple circuits. Most of the time it's just a rusty battery contact or some piece of dust/dirt shorting something. I have next to no knowledge about electronics. But I know that electricity always flows back to the source. So ID the main circuit, secondary circuits, and so on and so forth. I get to be the hero when my child's face lights up when her toy works again!
I enjoyed seeing your troubleshooting approach. I am amazed that there as so many circuit boards that are tossed in the trash, and replaced with an entirely new one, when there is only a small part needed. I am new to electronics, but I find it interesting. I looked into a course online, but it was geared toward people who work inhouse for companies. It required a lot of expensive testing equipment. I really just want to diagnose problems quickly and fix them. Thank you for making this video!
Woh, your knowledge is fantastic. Came across this video a second time and had to comment. The fist time I saw it was 24hrs late; I’d just thrown out a tv which was dead and I reckon i might have had a chance to fault find using your method and past knowledge. Second time watching was just in awe of how you did it.
You have my Fluke. I found mine in the trash - three of them the factory threw out. It was the first electrical thing I ever repaired. All I had to do was clean the terminals on the display board. Still works 30 years later.
Thank you, this video was very helpful to me in understanding electronics repair. I have a Mac classic I've been working on, and it will only boot if the voltage rails are lower than their correct voltage. This has helped me understand the troubleshooting process a lot better.
Really helpful stuff, Richard. Thank you. It's great that you take your time with the board and explain things outside what is strictly necessary for the repair, which makes for a very interesting video.
Amazing video. I pretty like your explanation. I need to repair a pcb that looks simple bit I haven't got enough knowledge to fix it. Your video encourages me to go into the eletronics field so I one day I can learn how to repair eletronic equipments. Great video
Nice video on repairing circuit boards with no schematic. This is how I learned back in the '70s. However, your phone's notification sound was driving me crazy because it was the same as mine.
10 mins in and what I've gathered is that you should check for continuity between the power inputs to the transformer, and there are breakers and current onset regulators between the power in and the transformer. Once that is verified, you can move to the output of the transformer, to the bridge rectifier's outputs that power another section of the board. Pretty cool. I feel like watching a few of these would give me a sense of what kinds of words get printed on boards.
I truly enjoy listening and watching your knowledge , the passion .thank you for showing how to troubleshoot , a lovely way to save money and learn how to not be wasteful. Excellent job 👏
I got 4 to 7 different amd to gtx 570 to 580 and 1060 to 1080, If I pay for shipping and back do you need any cards for upcoming videos who do I contact, don't really care how long it take, bought equipment but so many other things in life and haven't been able to get around to repairing them all. Then I have 2 other cards could use for the parts. Like fixing stuff and great at fixing about anything by just watching anyone else do it but soldering like my dad use 2 ages ago never been a strong suit or just beyond horrible if not 99 percent perfect. Then also whatever donations to the channel be good with also. No big deal either way, found the channel months ago and was in discord but still just sitting on a shelf and just haven't been able to get around to fixing them. Thanks might not be worth it any which way but thanks I will learn how to one of these days glad I found your channel very way better than any other ones.
Oh dear, De Longhi it says on the label. Don't know if it is coincidence or not, but we've had 2 De Longhi coffeemachines and they both failed very quickly. Love the way you explain all this. Thank you very much, it helps a lot.
I really enjoyed this video this is the first time that I saw your channel and I clicked on it and I enjoyed it. I'm an older guy I'm 57 years old I can't believe that but it's true I worked in robotics repair but mostly management for a great deal of my adult life but I never really got into board repair or even was interested in components or board level troubleshooting it just cost too much because I worked in the biotech sector pharmaceutical drug Discovery things like that and they needed machines repaired yesterday so it was pick and place mostly. Sometimes boards were repaired back it whatever manufacturing facility the robotics platform came from but that was up to each facility. I have recently gotten into Arduino designs because there was a couple of projects that I've wanted to do and I discovered I kind of have a knack for it I've been learning for a couple of weeks and I've already made some pretty complex board level designs and products that I could actually sell if I wanted to surprise the hell out of me that's for sure. My first project was simple controlling LED strips using an infrared motion detector predicated on a light dependent diode value but so basically if it was dark enough in the room the rest of the software would be considered and powered these led strips based on a value returned indicating the relative lightness or darkness and brightness or dimness of the strip so pretty simple but I hate to figure out how to control 5 volts from a 12 volt supply so I had to learn about how to properly integrate voltage regulator with the proper capacitors Etc I'm also an amateur chemist so I built heating mantles based on this triac circuit to control variable amperage for the coils and it worked quite well. I think I missed my calling LOL I know these are simple things but I've only been doing it for a couple of weeks and I understand how to program and upload my finished program to a small Ic for deployment. I don't think I'll be throwing as many things away I'll try in trouble shoot them and I have subscribe to your channel so thank you very much
Williams pinballs used zero-crossing circuits in later machines to control dimming of the general illumination lamps. It was a nice effect for background lighting
Just happened to find this video and I have to tell you how you've inspired me. I'm an industrial electrician in my late 40's and have always had fun poking around circuit boards since I was a little guy. I never considered doing this for money. I'm not terribly knowledgeable about circuit board troubleshooting but I've had all the training, I just need to apply it and remember. We have a recycle bin for electronics where I work and I make daily trips to it to find cool stuff to investigate. I also build retro-arcade cabinets from old CRT televisions I get from there. This video just made me think that maybe there's a reason for all my electronics hording if I just apply myself further. Maybe this will be my little money maker when I get too old to turn wrenches. Thanks!
It would be interesting if the author would put a pinned post up telling us the outcome. Did the customer find any bad external components (like a shorted heater)? Did the board end up working? Thanks.
Excellent content (as usual) Richard! I appreciate the common sense approach to troubleshooting this. Great reminder at the end (on your summary) that you’ve repaired the board but now one needs to determine what caused the issue. If a person absently minded reinstalled the board and put power to it…out comes the magic smoke again.😡. Great work mate. I again learned from this video. Darrell - 🇨🇦
This is fascinating stuff. I have a bit of basic electronic knowledge and I always wondered how you could fix circuitry with no schematic, and now I know.
Thanks for this - very insightful. I’ve done my fair share of casual repairs for myself and at Repair Cafés but don’t really have a method as such, it usually takes me ages to figure stuff out - doing it ‘blind’ like this is challenging as there’s no way to test it - this one seemed simple however, I imagine others may have multiple failures. If gives me a bit more confidence that my random methodology does have some merit albeit time and mind consuming 😂
Try the knippex mini cutter. I know it's terribly expensive, but it's just that much better. I abused mine, prying an RF shield can off or something...busted the tip off one side. Bought a new set and chastised myself for treating a good tool that way.
Very Good... Well explained and far better and thorough examination than most i have seen online, Well done. Look forward to viewing more of your work in the future
i'm just in the process of trying to fix a coffee machine board and stumble upon this video. thanks so much! btw that board is from a delonghi primadonna or similar machine. Also, macina means grinder in Italian
For the really tough dogs with components that are just out of spec and slowly going bad - try using "freeze spray". A lot of times the coldness will bring back the component to normal for a little while and you can pin point the trouble.
excellent video! i especially like the chat about its easier to make money doing this type of repair than trying to repair gpu's. i have found that gas ignition and control pcb repair is quite lucrative in australia. there arent many aussie manufacturers so you can bet you can make it worth while for both you and the customer to repair it rather than. replace it. nice work
I was the senior engineer for the South West of the UK working for Deritent in the mid 1990s. The key is to test each component in turn, Mark it with a dot & move to the next. Back then, the boards were built with ASICS & single components.... not so many programmable like PAL, GAL & micro controllers. My region made a lot of money...& I mean a LOT! As the early moved into the years of more programmable & micros, it became much more difficult. I can't undestandcwhy you did not look at the yellow fuse F2... I bet it is oc
Very interesting video. Reminded me of the good old days when i repaired industrial and Marine Navigation and communication electronic equipment. 3570 is a date code, meaning it was manufactured in the 35th week of 1970 Looks like an old board. It would help a great deal if you could get hold of the circuit diagram.
Hi, I am a computer software engineer with a strong interest in electronics and I think this video was just excellent, and I appreciated your advice at the end, excellent idea to get work in this field! I am a novice in electronics, can you please explain how you use the Ohm measure to test components, ie, I think in this video you identified something where the Ohms was lowest out of all the readings but I didn't understand why that is? Thank you!
I'm a newby to this field of work. Your vid really expanded my perspective on elec. diagnostics & repair . Thank-you and I'm looking forward to watching more of your vids !!!
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How to Recover Data from Corrupted Hard Disk for Free (2024) : bit.ly/4ffBoNB
Having spent the majority of my life in electronics ( Radio Rentals, Colourvision, Chandos to name a few) and having attained two degrees I still revert to basics when fault finding. This is a skill that never leaves you, don't forget that just because you find one fault doesn't mean there are not others! Keep up the good work, we need more younger people in the industry to combat the throw away society we have built.
Andrew Doherty I totally agree. Radio Rentals eh? I actually thought about 10 years ago, that these skills would die out with the last of my generation. Fortunately thanks to the internet, increased awareness of environmental issues (we all understand now that we have to change our ways) and a lot of good guys out there on forums and elsewhere sharing old school knowledge, I'm now sure that is not the case. It feels like there is a whole renaissance going on with younger people getting interested in repair now 😁
As long as there are teachers
there will be students....
War and supply chain issues will increase pressure for repair over replacement.
Andrew ,,,,
( MY man ) ... This is an extraordinary time. Interactive communications for the people ! Thank you for adding to the mindset of repair, not junk, the gear that got us here. We need a massive influx of workers to undo all the waste that is overwhelming the planet.
Your comment is very helpful to me and other readers.
I have gear that I refuse to let go ... hopefully I'll bring back to the second life that is well deserved. Thanks again Sir.
Yeah
This is a great electronics repair refresher. Just last week I was able to repair a $5k KitchenAid refrigerator's main board with a broken fuse caused by a shorted rectifier. I had no access to circuit diagram nor does the manufacturer provides it. The board is $650 brand new with a 3 month wait and $500 of factory repair labor, and I was able to fix it with $3 in parts and knowledge in electronics repair.
Unbelievable
Looking to do the same with an Air conditioner pcb board. Wont turn on
Slow clap
Good work. Right to Repair !
@@emilnilsson4320 ?
For anyone interested... Handy Andy took the PCB back to the client yesterday afternoon, with strict instructions to check for a short circuit heater element before trying it. This morning before I got up out of bed, I was just thinking about that negative 5V regulator (79M05) and what it may have been doing. I often think about stuff like that, I guess I'm electronically minded through and through LOL.
So anyway, here is my take on it, though I no longer have the PCB to check this.
I think the 79M05 is connected like this: The PIC18 needs a positive 5V supply and yet the Vcc (power in) of the PIC18 micro-controller will be connected to 12V from the transformer and bridge rectifier. The 79M05 minus 5V regulator then holds the 'ground' pin of the PIC18 at exactly 5V less (more negative) than the +12V supply.
This means the PIC18 has a +5V supply but it is referenced from +12V.
Now why? Well there are two relays on the PCB with 12V coils and the PIC needs to switch them on or off. There are two little transistors and diodes near the relays (I checked the diodes). I think the transistors are probably P Channel MOSFETS and switch power to the relay coils, so the P Channel MOSFET connects from +12V, to the relay coil positive end, and the other end of the coil connects to ground. This means the MOSFET can supply the 12V the relay needs to turn on.
To switch the MOSFET off, the PIC18 has to put 12V on the Gate and to switch it on is has to put *less than* 12V on the gate. Because the circuit designer connected the +5V Vcc pin of the PIC18 to +12V it can easily send +12V or less to the P-MOSFET gate and therefore switch the 12V relays with the minimum of components. Simples ehh?
PS the diodes by the MOSFETS will be to stop back EMF when the relay coils turns off 😉
@Mr Guru Bear in mind I am not 100% sure that the circuit works this way, it's just me picturing in my mind why it would have a 7905 negative regulator on a positive 12V supply. And the above is my best guess, would you go along with this being the likely circuit design for the reason I thought (ease of driving 12V relay coils). I don't suppose it is any more or less reliable than a 7805 or even a buck converter, as you mention. 🙂
Good fault diagnosis but something odd / bizarre. You can use a negative supply on a PIC to invert signal states but if you put 12V on Vdd and -5V on Vss (or reference any of the GPIO pins to +5V with -5V on Vss) then it's bye-bye PIC. I suspect the -5V is being used for something else as well, because they could have easily used a positive 5V regulator to power the PIC and then the PIC drives n-channel MOSFETs to turn on the 12V relays.
@@ralphj4012 See my pinned comment for my detailed thoughts on this.
I believe the PIC Vcc is connected to 12V and PIC Vdd is connected to the output of the 79M05 to set the voltage at that point to Vcc less 5V which would be +7V with reference to the negative end of the bridge rectifier. So the PIC still has a stable +5V supply between Vdd And Vcc, just not with reference to the negative end of the bridge. Although the 7905 is a negative 5V regulator, it doesn't to have output -5V with respect to ground, it could be -5V with respect to +12V 🙂
@@LearnElectronicsRepair Indeed, but onnecting the common and output of a linear regulator together to create a voltage subtractor is odd (unless they were intending originally to create a current source circuit then chaged their mind). Maybe they had a load of 79M05's to get rid of.
@@LearnElectronicsRepair +7V is still higher than the (2.0V to 5.5V) input voltage of the PIC. Too bad we'll never know for certain what's going on.
As a 43 year old learning electronics repair.
Your videos are perfect for me.
I am so interested from start to finish.
Your teaching is very good.
26:00 Italian here! Let me translate some words for you:
Macina -> Grinder
Pompa -> Pump (pretty self explanatory)
Motore -> Motor
Sonda Flusso -> Flow Probe
By the way, great video! Very easy to follow even for a beginner like me, I actually guessed some things right as you were going along the board
The direct English translation of motore is motor, not engine. They're often used interchangeably, but are actually very different things.
@@SwapPartLLC Ah yes! I always mix them up, I'll fix that.. In this instance "motor" is more appropriate
Sounds like its from a commercial Battista machine - especially if it's Italian!
Haha, Romanian here, you don't need to translate. Cheers, mate!
@@milutzuk Heck yeah :D
Sounds like you worked for a similar firm as I did: Deritend. A board like this should take less than 10 minutes to diagnose. My tips from 35 years in electronics fault finding like this:
1> Follow the current, follow the voltage. High energy is a vulnerability.
2> Follow the heat, look for burns & heat toasting.
3> Ignore the intelligence (micro). If it is damaged you can't get it anyway because it contains firmware.
4> Resistors fail by increasing value, almost never by reducing, all the way to open. In circuit they can ONLY reduce in value. If it reads less than the marked value it is likely OK.
5> Electrolytic capacitors always fall in value, they cannot rise. They don't like heat. The ones near heat sinks will fail. usually they bulge if bad. If all else fails, swap them all out anyway.
6> Measure each component, concentrating on the low hanging fruit. Mark it with a dot from a marker pen if good, move on. The last check of a suspect component should be desoldered to confirm it is bad.
7> Mechanical devices like switches & relays are unreliable.
8> Connectors are reliable but their solder mount pins are not because of mechanical stresses.
9> Heavy things which are soldered are vulnerable for mechanical reasons.
10> Nearly every fault will have a visual clue.
11> Closely, inspect solder side with magnifier around through hole pins.
12> If you have two boards you can VI trace compare.
from a 17 year old dude fixing tape players, this is a very good skill to have and a really informative video
My brother is an Electrician and asked me how can you fix a board if you do not have the schematic for it. This is how to do it just like you did. I make my own schematic and my brother was impressed that i can do that as I have never taken any course on electronics.
please refer to some English videos where I can learn basic electronics and also this type of solution.
You just took the card and drew a schematic for it. This is very impressive. This is much easier to do with consumer electronics. I totally agree with that. The power circuits are much more easier to track because they are simpler. Most of them are low power electronics and they don't need lots of components or control circuits like one would find in a computer part. I love your videos because you don't go like "This shows this symptom so this component is faulty." You start by doing a visual inspection and then check the connections. After this, you draw the circuit and think about what might go wrong and why it might go wrong. You don't just teach how to repair something. You try to teach it with the basics. Even though this makes the videos long, every second is worth it. You used to upload PSU videos and I hope I will see some more of them in the future. Great job.
Thanks. I will certainly do some more PSU tutorials in the future, don't worry.
@@LearnElectronicsRepair Yay. My switching power supply let out the magic smoke when it overheated. I replaced the transistors, but the protection circuit is still activated and I'm stumped. I left board electronics in the 80s and admit, I've lost it since. Stupid dark side (I.T.).
Good that you're making these in detail videos. Most of the laptop or macbook repair channels have very poor understanding of electronics.
Thank you, this will be very helpful.
As a latecomer to hobbyist electronics, I'm dumbfounded why RUclips have never presented your channel before.
Your diagnostics explanation is second to none. Great video. Thanks. I will subscribe, & check out some of your other efforts.
Not to mention the satisfaction of a successful repair using your mind as the main tool.👍
30:58 “Try the Triac”. That’s gold! 😹
That comonent tester you showed off is genius.
Until now I didn't knew something specific like that existed.
You Sir, just bought yourself another subscriber. I'm a qualified electrical Eng that used to work in office automation repair here in New Zealand, been a long time since though so your channel is now integral to my brushing up on PCB faultfinding! for that I sincerely thank you :)
brilliant delivery and diagnostic skills that make a seasoned man green with envy!
wait up a while, electrical and electronics are different animals here.
Electronics tends to be any voltage but mainly below 5v electrical tends to be specific to 240v , 120v in some countries, but generally known as main voltage.
Electronics would normally cover anything up to and including a mains input...... I have a great story on that where I covered my arse well with 3 or 4 colleagues and 2 group managers when a display unit went up in a cosmic blue smokey haze, like I warned them it could, and was assured it did not matter as no one else would ever need to mess with the guts. .
Not sure what I liked more, probably having all the emails where I pre warned them and they responded it was not an issue and they decided to escalate it to their group manager and my group manager .
Forwarding those lies they told was a choice they made when questioning my honesty I guess, . they all new I kept very good notes on everything, covering my arse was never an exception.
Great video, I am a self employed coffee machine service engineer UK, have been repairing commercial coffee machines for 35 years (make a good living) I suspect it was the heating element that blew which takes out the triac (very common) I replace many triacs BTB16 (16 amp) I also always check the opto coupler/isolator as well. I studied industrial electronics for four years in the 80s/90s so this helps with repairing some of the problems on the boards.
It's always good to watch an experienced technician/engineer work. The short rant at the end is very sound advice, i started learning about electronics out of pure curiosity and ended up coming up with a great side hustle just repairing small stuff, especially heaters, old game consoles and lcd monitors/tvs with basic knowledge of electronics.
Glad, you mentioned the possibility of short to ground. Because some people will miss this obviously dangerous situation. Thanks for fixing "anything."
Love these videos, im a service tech 30 years and do a lot of fault finding, everyday is a school day when it comes to electronics repairs.
Great video! I have been in electronics for 16 years now. It definitely comes down to the fundamentals. There may be different principles when dealing with different types of electronics (AC, DC, RF, etc.), but all electronic components are made of the same basic parts. Even if you know nothing about what you are looking at, you can learn a lot by looking up datasheets and just banging out various components with a DMM. Even better if you have a good, working example to compare measurements with!
Hi i really want to learn more about electronics and its fundamentals with practical knowledge any tip can I get because I am almost 16 year old, thanks for the help.
and occasionally luck?
years ago, had one of the chinese TIG welders fry itself. never actually fixed it mostly as my lab pup at the time chose to chew the main board up... but i did figure out it was the h bridge driving the AC inverter section (AC/DC for ali) having issues.
um, but as i cannabilised various other parts, i found a relay wasnt working... something involved in the HF start...
fast forward to a month or two ago. plasma cutter, HF starts playing up.
took me all of two seconds to diagnose... relay. default is to close when powered up, open once an arc is formed and current starts flowing... wasnt closing.
see how long the replacement holds up. if it misbehaves i got the answer for it... mercury wetted!
I really appreciate you the way you explain this stuff. Showing how to troubleshoot a problem on a board you know very little about is one of, if not the biggest, missing links for many people trying to learn these skills. Watching you walk us through how to figure out what might be expected from the components on an unknown board 'in the real world' is what seems to be missing from many similar channels that I've seen. Looking at your list of videos, there's many more useful and educational videos to keep us busy for some time! Subscribed. Thank you.
Just stumbled across the channel, I started working in an electronics repair company repairing PCB's very much like these (domestic appliance) at 16. I'm now 30, diverted into automotive electronics and machine maintenance. Very nice to see some of my old trade on RUclips especially now knowing what I've learned over the years!
The way you explain all of what you're doing during the repair is just awesome. Another thing that made me happy about this video was seeing you took a few minutes to explain - or refresh - what is a TRIAC and how it works. It helped me a lot on understanding how it operates on the board and how it is related to the failure (short), since I've studied TRIACs some time ago.
You've got a new subscriber.
This channel is a gem to find. Thank you, Sit for your generosity of knowledge and your dedication to being thorough with your efforts to share it. I truly appreciate your content.
What a lesson! Graduating as a mechanical engineer, now close to retirement have found the world of circuits and electronic components which is plenty of fun.
Could watch your videos all day mate , love to be a fly on the wall in there , id be like a sponge soaking up everything . Did my first ever laptop motherboard repair tonight , shorted cap on main power rail, laptops worth about 500 quid , its such a good feeling when your passion starts paying off
My background is in chemical engineering, but I dabble in some electronics repair / upgrade work for cars as a hobby! This video was very inspiring, I really appreciate it. It has given me some great food for thought for the next potential side hustle! Thank you :)
Thank you, I am a commercial coffee machine engineer in the Uk, The electronic fault finding nd repairs of boards. is currently not something I would consider.
but after seeing your video plus ordering a triac tester. I hope to develop, not just for coffee machines. Im looking forward to learning more from your videos. Thank you.
The detailed step by step explanations on the various components and their working aided me a tonne. Cheers mate.
A mate of mine is a gas fitter & he says it breakd his heart judy throwing boards away because his firm just send him in with replacement boards and he told me how much they cost even for just refurbished PCBs.
After I picked myself up off the floor he rummaged in the van & I've now got a box full of faulty PCBs.
So I'm after learning. Step by step is ideal for me (Asperger's lends itself to methodicalness) snd I've just discovered your channel.
To say "I'm all ears!" would be a massive understatement.
😀☮️
Edit: Loved it! Absolutely blindin' mate! That Peak Atlas would pay for itself on day one.
I was looking at a cheaper one but the Atlas didn't invent 2 resistors. That sort of thing could throw you off at the start.
Ok, off to watch another. Subbed with a head full of ideas! Nice one! 😜
This was fascinating from a person who knows little to nothing about electronics. Love watching someone explore something in a way that explains a lot. Definitely subbed. I like the bit of advice toward the end as well.
Your “quick rant” is bang on Rich. It’s also about reducing electronics waste too.
Now the coffee shop is back up and running with the machine and coffee drinkers can get their espresso fix too.
Like you say too it’s easily worth $100 to them. And it would take less than an hour and hardly anything on the components and consumables.
I just replaced a rectifier diode (in a bridge rectifier) on someone es welding machine wire motor. Part was less than £2 and he was over the moon as it is his favourite and best machine.
Loving your videos Rich thanks. I have you playing in the background whilst I’m tinkering in the workshop.
You are master! I repair my Keyless Entry Receiver in my Jeep thank your clip! Electronics is black magic to me. but according to the methodical fault finding I checked the paths from the connector through the board one by one and found breaks! I soldered the corroded elements and it worked!
I can't believe this is my second time watching this one. It's actually very interesting how easy Richard makes it look.
for me, that is really impressive
Great video! If everybody can have some tools and skills like yours, there would be so much lesser electronic waste in the world. Things are being manufactured at such a high speed and low cost, making repairing cost comparatively more expensive. Please keep the videos going!
I am a 19yo electromechanic from Argentina, I want to study Electronic engineering and your videos are of great help to me, I'm grateful that you are willing to share you knowledge and experience freely.
Fault searching was always a roadblock for me, I understand, mostly, the circuits, but when I get in front of a circuit I have no idea where to start
This is absolutely amazing. I've been doing hobby soldering since I was a child. I've been watching teardowns and repair videos on RUclips for around 10 years as well, but aside from knowing that there's a thing called "the one wire circuit" and what a "capacitive dropper" circuit does, I've never felt any more equipped to actually diagnose a piece of electronics that's hit my desk. This was extremely enlightening, and is honestly getting me really excited to try and look back at my many many many "backlog" project boards. I'm definitely not anywhere near being able to truly diagnose things on your level, but this is one of the first times the process has actually made sense to me as a methodology. Thank you!
This is great information! As a graduate student of electrical engineering who also does repair as hobby, this really adds to my knowledge.
How nice to see, the way I was taught in a TV repair shop, even though you had a good idea where the fault was, the engineer who taught me insisted I went through the whole process, which became second nature, lovely video.
Excellent tutorial for people like myself who are not exactly professionals but like to investigate faults sometimes with good results. Thank you so much for sharing 🙏
Thanks a lot! As a mobility aid repair tech trained up in the field, but having no background in electronics, this is very useful getting my head around the deduction process in fault finding...
I think I'll have a snoop around your channel to find more of these gems...
Gr.
P
This is the first video I've seen on the channel. I thoroughly enjoyed it. Greetings from Canada.
Welcome aboard. Also take a look at Learn Electronics Repair Discord server, I think you will like it 😉
Learn Electronics Repair is now on Discord! Come and join the fun and let's fix stuff together, it's free and a nice place to be.
discord.gg/vam6YC8vwU
What a fantastic repair from you Rich and what a great tutorial video!
I still believe this is the best Electronics Repair channel on RUclips!
Cheers, Darren
Good sir, thank you do much for your wisdom and knowledge. Being many years junior to you, i really appreciate your expertise in the field. As an EE, you definetly made me decide on starting electronics repair as a side job. All the good to you from Kazakhstan.
Just complete my graduation in electronics and communication.I have learned more from this video than my entire course🙂
Hi i am also currently in ECE 2 year any tips i can get for more practical knowledge
I’ve spent the majority of the past two nights watching RUclips videos on electronics repair and can say with certainty that I remain as confused as I was when I started watching last night.
Does anyone know how to find a self employed electronic repair person? Many factories would be interested in this skill and the service would be extremely useful!
yeah, it's true that learning how the basics, "pure electronic" side of things is a good, and even important step, not only can it be very useful , by learning how certain components are supposed to behave, eventually help you learn what certain part of a circuit is supposed to do witch can really help for testing and diagnosing it!!! haven't done tons of repairs myself so far, a few easy one here and there, so far i've mostly learned by using schematics and making my own stuff, like making diy shields to use with an arduino, or mod something. a lot of the components i use are all recycled from old stuff that either me or other peoples was gonna throw in the trash... in the beginning i've spent so many hours just tearing stuff apart to unsolder everything on the pcbs inside... XD but as my collection grew i'd often make research to find schematics i was able reproduce with what i had, for most off the chips i've pulled i would throw on a breadboard and study the datasheet, to then make and experiment with the most basic circuits needed to make them work! i still use a lot of those parts when experimenting to make something i want to build, but once i know it works and are ready to build the final permanent version, i do at least buy the most critical parts to make sure it last!!
sBeDs - you are doing exactly the sort of thing I was doing as a teenager, though it was all analog circuits then of course. If you want to not only learn, but master, electronics repair you are definitely going down the right track with what you are doing. Keep it up 🙂
@@LearnElectronicsRepair nice, and thanks!!! i've always loved to learn how things work, and how to make stuff myself, and electronics is definitely one of the subjects that interest me the most!!! And back at you, keep it up, your channel is already one of my favorite when it comes to electronics, the way you do repairs on camera and explain everything you're doing and why is just perfect!!!😝🙂
You mean to tell me everyone don’t start exactly like this. I bought my first computer just to take it apart. A week later I was a professional At bypassing WGA. And yes it paid the bills. People were gladly paying to remove watermarks. Some of those people still come to me religiously. Even though I quit working on computers around win 10 release.
I did the best repair to a Samsung TV I baked the processor board at 350F for 10 minutes. The 60 inch TV has been working for four years now. Has to be my all time best electronic repair.
I just learnt so much from this.
My Brother in law is a Master Electrician. They had an amp at the shop that would not work. All three electricians gave up on it as could not figure out the problem. I figured it out in about 10 min. The main transformer had a thermal fuse that was blown. I unwound the coil by hand, replace the thermal fuse and then rewound the coil by hand. Fix it.
How did you reassemble the coil
@@keylanoslokj1806 I pulled the end of the wire back around the center and kept doing that until I got to the thermal fuse. soldered in a new fuse then like a thread pushed it through the gap and rewound it. keep it as close to the same as when I unwound it. Reconnect the wire to the circuit. It is like threading a needle and threat but wrap it around the metal core. Do not take the metal core or laminate apart, just unwind the wire.
Brilliant - again! Can't remember whether I mentioned it but this week - thanks to your videos - I fixed an old function generator. The fault was not one of the thirty or so solid state components but two short circuit tantalum capacitors shorting the positive and negative rails to earth.
Thanks for the video. Really enjoyed the signal flow, explaining the parts in further detail, how they work, and then finding the fault and testing. Look forward to the next one!
I got my start with TV repair. Can't get service manuals and schematics for most of them now, and it's just not worth reverse engineering and tracing out circuits on a TV which can be replaced for $200. I don't do it anymore, but I learned a lot from it and the skills apply to all electronics.
Funnily enough I also started (professionally) with TV repair.
I have learned a lot from your videos.
I always wanted to dabble into the world of electronics as I was always interested in repairing circuit boards and other board appliances myself.
I tip my hat to you, sir
I've recently been repairing my infant daughters toy electronics. Extremely simple circuits. Most of the time it's just a rusty battery contact or some piece of dust/dirt shorting something. I have next to no knowledge about electronics. But I know that electricity always flows back to the source. So ID the main circuit, secondary circuits, and so on and so forth. I get to be the hero when my child's face lights up when her toy works again!
Wonderfully explained the approach to the faulty stage applying the basic electronics,
even an amateur can grasp the way you have explained
I enjoyed seeing your troubleshooting approach. I am amazed that there as so many circuit boards that are tossed in the trash, and replaced with an entirely new one, when there is only a small part needed. I am new to electronics, but I find it interesting. I looked into a course online, but it was geared toward people who work inhouse for companies. It required a lot of expensive testing equipment. I really just want to diagnose problems quickly and fix them. Thank you for making this video!
Woh, your knowledge is fantastic.
Came across this video a second time and had to comment.
The fist time I saw it was 24hrs late; I’d just thrown out a tv which was dead and I reckon i might have had a chance to fault find using your method and past knowledge. Second time watching was just in awe of how you did it.
I'm a beginner and this is absolutely amazing!!!
You have my Fluke. I found mine in the trash - three of them the factory threw out. It was the first electrical thing I ever repaired. All I had to do was clean the terminals on the display board. Still works 30 years later.
Thank you, this video was very helpful to me in understanding electronics repair. I have a Mac classic I've been working on, and it will only boot if the voltage rails are lower than their correct voltage. This has helped me understand the troubleshooting process a lot better.
Really helpful stuff, Richard. Thank you. It's great that you take your time with the board and explain things outside what is strictly necessary for the repair, which makes for a very interesting video.
Amazing video. I pretty like your explanation. I need to repair a pcb that looks simple bit I haven't got enough knowledge to fix it. Your video encourages me to go into the eletronics field so I one day I can learn how to repair eletronic equipments. Great video
Nice video on repairing circuit boards with no schematic. This is how I learned back in the '70s. However, your phone's notification sound was driving me crazy because it was the same as mine.
10 mins in and what I've gathered is that you should check for continuity between the power inputs to the transformer, and there are breakers and current onset regulators between the power in and the transformer. Once that is verified, you can move to the output of the transformer, to the bridge rectifier's outputs that power another section of the board. Pretty cool. I feel like watching a few of these would give me a sense of what kinds of words get printed on boards.
I truly enjoy listening and watching your knowledge , the passion .thank you for showing how to troubleshoot , a lovely way to save money and learn how to not be wasteful. Excellent job 👏
I got 4 to 7 different amd to gtx 570 to 580 and 1060 to 1080, If I pay for shipping and back do you need any cards for upcoming videos who do I contact, don't really care how long it take, bought equipment but so many other things in life and haven't been able to get around to repairing them all. Then I have 2 other cards could use for the parts. Like fixing stuff and great at fixing about anything by just watching anyone else do it but soldering like my dad use 2 ages ago never been a strong suit or just beyond horrible if not 99 percent perfect. Then also whatever donations to the channel be good with also. No big deal either way, found the channel months ago and was in discord but still just sitting on a shelf and just haven't been able to get around to fixing them. Thanks might not be worth it any which way but thanks I will learn how to one of these days glad I found your channel very way better than any other ones.
Oh dear, De Longhi it says on the label. Don't know if it is coincidence or not, but we've had 2 De Longhi coffeemachines and they both failed very quickly.
Love the way you explain all this. Thank you very much, it helps a lot.
Interesting!
Thank you for taking so much care in making this vid. everything from the position of the camera, the data sheet cross ref, was important to me ..
I really enjoyed this video this is the first time that I saw your channel and I clicked on it and I enjoyed it. I'm an older guy I'm 57 years old I can't believe that but it's true I worked in robotics repair but mostly management for a great deal of my adult life but I never really got into board repair or even was interested in components or board level troubleshooting it just cost too much because I worked in the biotech sector pharmaceutical drug Discovery things like that and they needed machines repaired yesterday so it was pick and place mostly. Sometimes boards were repaired back it whatever manufacturing facility the robotics platform came from but that was up to each facility. I have recently gotten into Arduino designs because there was a couple of projects that I've wanted to do and I discovered I kind of have a knack for it I've been learning for a couple of weeks and I've already made some pretty complex board level designs and products that I could actually sell if I wanted to surprise the hell out of me that's for sure.
My first project was simple controlling LED strips using an infrared motion detector predicated on a light dependent diode value but so basically if it was dark enough in the room the rest of the software would be considered and powered these led strips based on a value returned indicating the relative lightness or darkness and brightness or dimness of the strip so pretty simple but I hate to figure out how to control 5 volts from a 12 volt supply so I had to learn about how to properly integrate voltage regulator with the proper capacitors Etc I'm also an amateur chemist so I built heating mantles based on this triac circuit to control variable amperage for the coils and it worked quite well. I think I missed my calling LOL I know these are simple things but I've only been doing it for a couple of weeks and I understand how to program and upload my finished program to a small Ic for deployment. I don't think I'll be throwing as many things away I'll try in trouble shoot them and I have subscribe to your channel so thank you very much
Williams pinballs used zero-crossing circuits in later machines to control dimming of the general illumination lamps. It was a nice effect for background lighting
I appreciate the time you took to explain this, I repair appliances and want to offer board level repairs
Just happened to find this video and I have to tell you how you've inspired me. I'm an industrial electrician in my late 40's and have always had fun poking around circuit boards since I was a little guy. I never considered doing this for money. I'm not terribly knowledgeable about circuit board troubleshooting but I've had all the training, I just need to apply it and remember. We have a recycle bin for electronics where I work and I make daily trips to it to find cool stuff to investigate. I also build retro-arcade cabinets from old CRT televisions I get from there. This video just made me think that maybe there's a reason for all my electronics hording if I just apply myself further. Maybe this will be my little money maker when I get too old to turn wrenches. Thanks!
It would be interesting if the author would put a pinned post up telling us the outcome. Did the customer find any bad external components (like a shorted heater)? Did the board end up working? Thanks.
Excellent content (as usual) Richard! I appreciate the common sense approach to troubleshooting this. Great reminder at the end (on your summary) that you’ve repaired the board but now one needs to determine what caused the issue. If a person absently minded reinstalled the board and put power to it…out comes the magic smoke again.😡. Great work mate. I again learned from this video. Darrell - 🇨🇦
RUclips recommended your video to me, I'm now a subscriber
This is fascinating stuff. I have a bit of basic electronic knowledge and I always wondered how you could fix circuitry with no schematic, and now I know.
Thanks for this - very insightful. I’ve done my fair share of casual repairs for myself and at Repair Cafés but don’t really have a method as such, it usually takes me ages to figure stuff out - doing it ‘blind’ like this is challenging as there’s no way to test it - this one seemed simple however, I imagine others may have multiple failures. If gives me a bit more confidence that my random methodology does have some merit albeit time and mind consuming 😂
Thanks for the explanation!
Question: Did you clean the scorched place and used some solder mask later?
Try the knippex mini cutter. I know it's terribly expensive, but it's just that much better. I abused mine, prying an RF shield can off or something...busted the tip off one side. Bought a new set and chastised myself for treating a good tool that way.
Very Good... Well explained and far better and thorough examination than most i have seen online, Well done. Look forward to viewing more of your work in the future
i'm just in the process of trying to fix a coffee machine board and stumble upon this video. thanks so much! btw that board is from a delonghi primadonna or similar machine. Also, macina means grinder in Italian
As someone who repairs electronics as a hobby. It's always the thingy on the heatsink
good god this is amazing, ive been looking for material like this for years.
For the really tough dogs with components that are just out of spec and slowly going bad - try using "freeze spray". A lot of times the coldness will bring back the component to normal for a little while and you can pin point the trouble.
Yes that is a very useful technique, plus using a hair dryer to warm components as well.
thank god for captions...lol. great lesson though. 😆👍
Just found your channel and it is brilliant, I’m self taught in electronics repairs and got pretty good at swapnostics. This has been a great help
hi Sir ...good day , For circuit board how do i check the resistance or capacitance (TINY surface mount components) when i cant see its values.
excellent video! i especially like the chat about its easier to make money doing this type of repair than trying to repair gpu's. i have found that gas ignition and control pcb repair is quite lucrative in australia. there arent many aussie manufacturers so you can bet you can make it worth while for both you and the customer to repair it rather than. replace it.
nice work
Ur inspiring dear sir! I’ll use you as my guide and mentor in chasing my dream in becoming an electric engineer 🙏🏿
Had an Italian coffee machine at work some years ago. One cost 7k and one was about £12k, so well worth repairing..
That was a nice journey through out diagnostics of a pcb board.
I now understand Triacs. Great explanation.
I was the senior engineer for the South West of the UK working for Deritent in the mid 1990s. The key is to test each component in turn, Mark it with a dot & move to the next. Back then, the boards were built with ASICS & single components.... not so many programmable like PAL, GAL & micro controllers. My region made a lot of money...& I mean a LOT! As the early moved into the years of more programmable & micros, it became much more difficult.
I can't undestandcwhy you did not look at the yellow fuse F2... I bet it is oc
Very interesting video. Reminded me of the good old days when i repaired industrial and Marine Navigation and communication electronic equipment.
3570 is a date code, meaning it was manufactured in the 35th week of 1970
Looks like an old board.
It would help a great deal if you could get hold of the circuit diagram.
Hi, I am a computer software engineer with a strong interest in electronics and I think this video was just excellent, and I appreciated your advice at the end, excellent idea to get work in this field! I am a novice in electronics, can you please explain how you use the Ohm measure to test components, ie, I think in this video you identified something where the Ohms was lowest out of all the readings but I didn't understand why that is? Thank you!
I'm a newby to this field of work. Your vid really expanded my perspective on elec. diagnostics & repair .
Thank-you and I'm looking forward to watching more of your vids !!!