To learn electronics in a very different and effective way, and gain access to Mr Carlson's personal designs and inventions, visit the Mr Carlson's Lab Patreon page here: www.patreon.com/MrCarlsonsLab
I can't count the number of times in the 80s and 90s when I worked on Japanese-made products when the glue on the board to hold down components would become conductive and just give me fits. It was very common in VCRs and TVs.
Problem with most switch mode supplies is that schematics for them are not available. If you would have found the switching transformer had an open primary, that would probably have been that?
Could we solve this by using component tester to show high leakeage? If we dont have curve tracer, can we use simple component tester and pay attention to leakeage current? Its Reverse Current, Ir? Or I am wrong?
Same here. I'm an industrial electrician now. Thanks, Mr. Carlson. You'd be surprised how much these videos you make have given me joy. There was a time when i had none, and now I have a family and career i love. I'll watch every video you ever put out.
Lol, I don't know about it being a treat, more like scary, cause I have one of these rigs. I need to make sure and put Mr.Carlsons vids in a playlist in case mine dies
2nd time watching this, wonder how many times we thought a diode was okay but it actually was not do to leakage. Your repairs are impressive and your patience. Great video always worth another view. I think I will check out your first repair of one of these years ago.
I've been following your channel for 7-8 years and I built your curve tracer some time ago in a stand alone box and use it with a Tek 475. A while back I also bought a Fluke 6071A RF sig gen that was completely non-functional for cheap that had a myriad of issues (and holy cow is it heavy and hard to work on!), and I slowly brought it back to life. It had a completely unstable output carrier frequency that would wander all over the place and I eventually traced it back to a leaky TL084 op amp in the hetrodyne oscillator board that I found using your curve tracer. I knew almost nothing when I started in electronics in 2015, so thank you Paul to your channel and patreon and the knowledge you bring.
Liked how you methodically troubleshoot the switching power supply, finding a leaky zener diode with a curve tracer proved it was bad where the conventional diode check on the meter did not see that issue. Definitely took the mystery out what's needed to make the switching power supply work. Great job!
What I would have liked is to see another method to find this issue, since a multi-meter was unable to do it, but hardly anyone is going to have a curve tracer.
Loecurious,@@leocurious9919, An alternative would be to use a variable DC power supply and connect zener diode and your multimeter in series with the variable voltage source and look for leakage as you increase voltage. If you see a gradual increase in voltage before getting to the zener regulating voltage. You would then know the diode is leaky. Hope I explained it good enough for you.
@@leocurious9919 Realistically, a simple curve tracer can be built by anyone with an oscilloscope, old or new, plus a small transformer, one resistor and a set of probes. Mr Carlson's tracer is just a slightly more advanced take on the old "Octopus"-type tracer You sweep the x axis with a sine voltage, current limited (usually you do 1.5 to 5V to avoid damage to TTL circuits, and limit the current to maybe 1mA max due to a direct short) by a 1k resistor and read off the current with the resistor. A scope in XY mode provides the display, and since the resistor is 1k you read off mA directly on the scope, and volts across the X axis. Simple as that, less than ten components and you have pretty much the same curve tracer. Just search for "Octopus curve tracer" and check the images, you'll have a visual description of what I've just said. Diodes act the same way as on Carlson's video, resistors, capacitors and inductor all have their own "signature" curve. Combinations of them, too, are visibile and very informative!
All men have dreams. Some of us dreaming of having a workshop and knowledge of Mr. Carlson. I need a poster in my house. Not sure what my wife will say though…
Very good! Switchers are a black art... nice to see one repaired. Many ham radios just expect 13VDC, the power supply is external... so now I'm more determined to never buy a unit with an internal one! Been using Yaesu since 1991... good stuff.
HO yes, feedback loop, big voltages, lots of power... I'm not an expert so what I usually do is find the loop, open it, and start from there by seeing what it does section by section with a dummy load. Of course, if the first thing it does is explode, you know you had RIFA caps somewhere...
My experience told me I would have never figured that out. I have no tool that would have let me diagnose a zener diode failure like that of even to check it past the multimeter. I probably would have just slapped a resistor in there and left it at that.
@@coll6 either substitution or a series resistor and power supply to see what it breaks over at would easily tell you. I usually went with substitution, as I kept a shelf full of parts in stock for repairs.
hey Paul, while about an hour and a half of time, it was well worth my time. I had heard of a curve tracer, but never have I seen it put to work to solve a problem. what an incredible piece of equipment. and you built it yourself, sounds like I need to get on your patreon channel. thanks mike
My late father had a FT2000 it was an amazing piece of kit, he would of loved your channel. When I see you repair radios like this it brings back many happy memories of me listening to the radio with him in his shack. Thank you so much for sharing.
Built the curve tracer. Ton of fun and a great learning experience. It's a great comparative tool. Fixed more than a few things quick with it. Paul's a genius.
That used to be a beginners project, with a complete discussion of theory of operation, back in the day. If there's one thing I've never declined, it wasn't another drink, it was offered free training. :)
Incredible! I was just handling the same supply for my FT-990 that I extracted over a year ago after replacing a couple of caps and left it in despair due to its complexity and my boot camp level trouble shooting skills! I took a peek at at a few days ago and gave up again. You've given me fresh wind in my sails to give it a sporting try! Thank you so much Mr. Carlson, you are an emissary of God! Dennis - W4ZOR
I remember in school seeing an instructor do a demo on Zeener diodes, they call it the knee voltage at breakdown/ rated voltage. It gave a more intricate picture. Enjoying your video. We just pulled a ABB 520 amp 600 DC volt DC contactor out of a CNC machine. It puked. Well back to work, now in Valparaiso, Indiana. Hugh Mc.
Outstanding troubleshooting video. Great analysis of the switch mode power supply and the technique of back feeding the 13.8VDC from the output to troubleshoot the output circuit and isolate the problem to the middle section of the supply. Nice use of the parts data sheets to obtain the starting voltage necessary for the IC to find out that it needed a minimum of 16VDC to start properly, which it did not have. Also fantastic demonstration of the use of a tracer scope to show the proper 'knee' of a diode whether it is a standard PN Junction diode or a Zener diode. Being a RF Communication-Electronics Instructor in the U.S. Marine Corps in the early 1980's teaching Basic Electricity, Basic Electronics, Radio Fundamentals, and Troubleshooting, I applaud your use of the current medium to be able to show your skills and experience on RUclips. Mr. Carlson congratulations on another successful repair demonstration. It is an honor to be a subscriber to your channel and providing you a thumbs up of every video I watch.
This one by Professor Paul Carlson a tough one. This shows Paul’s ability of electronic troubleshooting with Correct disassembly and correct alignment in assembly with QC checks per step. Big dollar troubleshooting and repair of a high dollar Ham Transceiver. Lot of information on using soldering iron and test equipment. Thank you Paul.
I have a curve tracer oscilloscope kit, which I rarely use. This video reminded me to use it more often. I certainly would have probably thought that Zener was fine.
Watching you repairing that PSU brings back memories of fixing 4kW SMPSU’s at my old company. Nobody else wanted to work on them. Takes a lot of caution and thinking outside the box, like breaking the loop, feeding external power to make sure the loop works, etc. so beautifully showed by you.👍👍👍
I already had a good idea on how switching PS worked but you just finalised my knowledge to a level that I am now pretty sure on how to debug them!! thanks!! proud to be a patreon user!
Thank you very much for sharing this experience! I enjoyed every minute of it and learned a lot! I’m currently trying to repair a faulty HP 8591E Spectrum Analyzer. Your in-depth analysis provided a lot of insight on the methodology and techniques useful in repair of any complex circuit!
I volunteer as a repairman at the Repair Café: Quite common is the failure of switching power supplies in devices that our customers bring in for repair. In switching power supplies, troubleshooting is often difficult because the overall function results from the interaction of many components. If one component is faulty, the whole thing will not work. Isolating the fault is often difficult when everything depends on each other. Thank you for pointing out that diodes and Zener diodes can also have leakage currents like capacitors. I did not know yet. Also important is your hint in this video how important the correct position of switching wires in the devices are for avoiding unwanted electromagnetic interference.
THANK YOU VERY MUCH SIR CARLSON IT'S A PLEASURE TO WATCH YOUR VIDEOS YOU TEACH US A LOT AND YOU EXPLAIN IT SO WELL THAT IT EVEN MAKES YOU WANT TO REPAIR AN APPLIANCE LIKE YOU DO THANKS AND GREETINGS TO ALL YOUR FOLLOWERS 🎉🎉😊
It was a real pleasure to watch such professional work with such excellent test equipment in expert hands. Great job finding the root of the problem! 👍🏻 It has been proven again that there are no poltergeists and curses in electronics, only bad components. 😁 Just a side note: instead of the curve tracer, if someone doesn't have one, you can use a laboratory power supply with current limiting and built-in ammeter, gradually increasing the voltage. If the resolution of the built-in ammeter is not enough, then you can connect the multimeter in the microammeter mode in series with the component under test. This is not so visual as the curve tracer, but it is also quite effective for finding leaking components.
Mr Carlson, you are a genius! As one who used to repair electronic equipment, and also teach the subject at college, I can only admire your patience and ability to follow a logical course in tracking down faults. I was always very wary in attempting to repair switching mode PSUs especially as here in the UK the mains voltage is 230V so you might end up following a trail of damaged components! I loved your curve tracer with its ability to display the characteristics of components where a multi meter might not reveal a fault such as leakage. Just one small point. It would be useful to have a brief introduction to the principles of operation such as why SWPSUs have a high frequency oscillator which switches on and off a power output stage. Otherwise a superb lesson in fault-finding techniques.
This is a testament to knowing what the capabilities of your test equipment. It's too easy to forget the limitations of what is perceived as a simple diode check! Great perspective on troubleshooting as well as awareness of your gear.
AMATEUR WORKING ON IT WOULD BE CORRECT MR CARLSON. IM AN AMATEUR AND I WOULD NOT DREAM OF PLAYING AROUND WITH SUCH A SOPHISTICATED RADIO. NICE ONE AS AWAYS
An avid long time hobbiest follower and listener from the Philippines🇵🇭😊😊😊 I just want to thank you Sir for sharing your knowledge and giving some insites lectures and tips for free about the intricate wisdom in the world of electronics. I really enjoyed watching your videos about restorations and repairs you've had made. Again, thanks a lot Sir😊 mabuhay🎉
Very good description on the fault finding and repair of this strange fault! The leaking zener, which required curve tracing to reveal, is interesting! Also, good tip to reverse feed the o/p to confirm FB circuits are ok. I have repaired and struggled with many switching power supplies and know they are "beasts" when they don't work, so this is very good info, Paul!
Wow, another awesome video, Mr. Carlson. Despite my rather meager knowledge of electronics, I love watching these videos. Years ago I worked in a VCR repair shop, so I have some knowledge, but again, it's minimal, as I worked mostly at the front. I know a good, OK great, troubleshooter when I see one. I don't think a lot of techs could have figured that out, nor would they have the great equipment to test. Your skills and knowledge are astounding. That curve meter (?) to check the diode leakage was amazing. Thanks for the trip through the circuitry, etc. Most excellent content. Cheers.
Thankyou Paul i learned alot for trouble shooting switch mode power supplys as i have a few in equipment i own...no problems yet but as you know its only a matter of time thanks again ...termiteaudio
Thanks for the video, a wonderful demonstration of diagnostics and a beautiful proof that the diode tester can't find everything. I can't imagine my workplace without a curve tracker, I have been confirmed several times with similar partial damage to the diodes. The last such damage happened due to the degradation of the glue used to fix the parts. Nice day 🙂 Tom
Great troubleshooting, tricky problem. Well explained. Most of beginners wouldn't be able to figure out leaky diode. I think you immediately knew where is the problem (from experience), but the video is prolonged for educational purpose.
Incredible stuff Mr Carlson (Paul) what i leant today is when testing zener diode's, not to rely on a simple multimeter reading, ie closed or open circuit depending on the orientation of the probe leads. and how your modified oscilloscope showed a completely different picture, and well done
Mr Carlson I have had switch mode power supplies not only eating my lunch but my dinner too! This was yet another outstanding video and now back to getting my "glow in the dark" Hammarlund HQ180A back in service that I have had since 1970 something.
I wish you would produce more videos on more recent equipment. Your structured approach to troubleshooting is extremely educational for me. There are very few people here producing content on that level.
That's a great troubleshooting video Paul. It really shows that a schematic and a curve tracer can go a long way in fault finding. You can never fully trust your multimeter when it comes to checking diodes. One of the first tools I aquired when I retired was a B&K 501a curve tracer. It's a great tool for characterizing transistors and zener diodes. I suspect, although you didn't show it, is that your curve tracer can be calibrated so that you can actually see the reverse Vz of the diode under test. Even so a curve tracer is great for fault finding or matching transistors. And yes I always seem to learn something from your videos....
Great Paul and this proves you would not of found the problem with normal equipment unless you just happened to replace those diodes with new ones. Very good video!
Thanks. I'm stunned at everyone of your videos. I'll admit, I have a long way to go before I'd ever touch that power supply. I have to chuckle that your leads and temporary connections hinder you the same as me. We emphasize ohms law but to add Murphy's law and you are so right.
I love your setup! It's so professional and warm at the same time. I also really like the topic. I've struggled to fix SMPS's for a long time. I'm getting better. Your two Videos on this subject are the main reason why.
Thanks so much for the video. Excellent to see an experienced tech reveal new knowledge! I have to admit the meter measurements would have fooled me. Today I learned something new. Now I have to go build a curve tracer🏃
Great video as always, Paul! I would love to know why the trick to test the Darlington transistor works (the initial dim light), and how you know to test for ESR vs leakage? Maybe a couple short videos on those tricks of the trade?
One thing about using a curve tracer such as a Huntron, for example, is KNOWING what a good component should look like. I have repaired a LOT of things just using my Huntron Tracker, as it saves me lots of time. Switchers are FUN!!! Especially if you CAN'T get a schematic!
Very thorough and informative. Paul, thank you. 👍 Your work inspires me to open the supply on a Mark V field I own, and determine if I can add that fourth filter capacitor.
this radio has a dc socket at the back. I had removed the switching supply, saved the money for repair and would feed it with a big lifepo battery. Thanks for the video!
Paul, have you considered renaming your channel to The Joy of Electronics with Mr. Carlson? I ask because you are most certainly the Bob Ross of electronics. Your ability to speak calmly while methodically explaining each troubleshooting and repair step in great detail is inspiring. Thank you for another great video.
Well done Paul. This one was a hard one! Someone had released all the Magic Smoke that thing had in stock and more haha. Nice FT-1000. Only other high quality videos about repairing these transceivers that i can remember are made by the Brazilian Electronic Engineer Ivo Muniz in his RUclips channel with the same name. 73 73
Fabulous video Paul. I have not read all of the 'comments', however I'm sure we have all struggled with 'switch mode power supplies' and the troubleshooting of them.
Great work Paul! Just replace that zener diode , after so many resets has dry out its main functions . Coping with that start up current . A source meter would be handy now .
wow what a great video, your methodical way of working your way through the problems is amazing, more of this please. Every man must have a curve tracer👌🤟
At 1:04:00 the 21 volt measured is not the startup voltage but the regulated voltage from the backfeed because the power supply was working at that point. You could have traced the startup voltage during power on time on a oscilloscope.
Gosh darn it Mr. Carlson, thank you for getting me into ham radio again and making me want to get my license. I love all of your repair videos on radio transcievers.
Reminds me of those old Panasonic VCR SMPS' with the 1uf 'bootstrap' capacitor that would dry-up, so the oscillator wouldn't get that initial kick ..usually right after a power cut! Lots of similar Zener and irksome output regulator issues in those, as well. Hours of fun! :)
To learn electronics in a very different and effective way, and gain access to Mr Carlson's personal designs and inventions, visit the Mr Carlson's Lab Patreon page here: www.patreon.com/MrCarlsonsLab
I can't count the number of times in the 80s and 90s when I worked on Japanese-made products when the glue on the board to hold down components would become conductive and just give me fits. It was very common in VCRs and TVs.
Problem with most switch mode supplies is that schematics for them are not available. If you would have found the switching transformer had an open primary, that would probably have been that?
Thank you so much...
Futaba does RC stuff dont they ??? controlers and servos . had few of there servos in rc cars and helis
Could we solve this by using component tester to show high leakeage?
If we dont have curve tracer, can we use simple component tester and pay attention to leakeage current? Its Reverse Current, Ir? Or I am wrong?
Man the FT1000 repair and modification video from 8 years ago was what introduced me to the channel... what a treat to see another one... good times.
It was the first video that I watched as well and then I was hooked : )
Same here. I'm an industrial electrician now. Thanks, Mr. Carlson. You'd be surprised how much these videos you make have given me joy. There was a time when i had none, and now I have a family and career i love. I'll watch every video you ever put out.
Same and this radio reminds of that.
Lol, I don't know about it being a treat, more like scary, cause I have one of these rigs. I need to make sure and put Mr.Carlsons vids in a playlist in case mine dies
Same!
2nd time watching this, wonder how many times we thought a diode was okay but it actually was not do to leakage. Your repairs are impressive and your patience. Great video always worth another view. I think I will check out your first repair of one of these years ago.
I've been following your channel for 7-8 years and I built your curve tracer some time ago in a stand alone box and use it with a Tek 475. A while back I also bought a Fluke 6071A RF sig gen that was completely non-functional for cheap that had a myriad of issues (and holy cow is it heavy and hard to work on!), and I slowly brought it back to life. It had a completely unstable output carrier frequency that would wander all over the place and I eventually traced it back to a leaky TL084 op amp in the hetrodyne oscillator board that I found using your curve tracer. I knew almost nothing when I started in electronics in 2015, so thank you Paul to your channel and patreon and the knowledge you bring.
Thank You for your kind comment, and feedback.
Liked how you methodically troubleshoot the switching power supply, finding a leaky zener diode with a curve tracer proved it was bad where the conventional diode check on the meter did not see that issue. Definitely took the mystery out what's needed to make the switching power supply work. Great job!
What I would have liked is to see another method to find this issue, since a multi-meter was unable to do it, but hardly anyone is going to have a curve tracer.
Loecurious,@@leocurious9919, An alternative would be to use a variable DC power supply and connect zener diode and your multimeter in series with the variable voltage source and look for leakage as you increase voltage. If you see a gradual increase in voltage before getting to the zener regulating voltage. You would then know the diode is leaky. Hope I explained it good enough for you.
@@leocurious9919 Realistically, a simple curve tracer can be built by anyone with an oscilloscope, old or new, plus a small transformer, one resistor and a set of probes. Mr Carlson's tracer is just a slightly more advanced take on the old "Octopus"-type tracer
You sweep the x axis with a sine voltage, current limited (usually you do 1.5 to 5V to avoid damage to TTL circuits, and limit the current to maybe 1mA max due to a direct short) by a 1k resistor and read off the current with the resistor.
A scope in XY mode provides the display, and since the resistor is 1k you read off mA directly on the scope, and volts across the X axis.
Simple as that, less than ten components and you have pretty much the same curve tracer.
Just search for "Octopus curve tracer" and check the images, you'll have a visual description of what I've just said.
Diodes act the same way as on Carlson's video, resistors, capacitors and inductor all have their own "signature" curve. Combinations of them, too, are visibile and very informative!
All men have dreams. Some of us dreaming of having a workshop and knowledge of Mr. Carlson. I need a poster in my house. Not sure what my wife will say though…
Listening under headphones. You did a good job not picking up the outside noise, I wasn't hearing anything but you. Great Video, thanks for sharing.
Glad you enjoyed David!
Thank you, I'm a patron member of yours.
Very good! Switchers are a black art... nice to see one repaired. Many ham radios just expect 13VDC, the power supply is external... so now I'm more determined to never buy a unit with an internal one! Been using Yaesu since 1991... good stuff.
Nice work! Switchers are tough to troubleshoot. You made it look easy, but it is the experience that does it.
HO yes, feedback loop, big voltages, lots of power... I'm not an expert so what I usually do is find the loop, open it, and start from there by seeing what it does section by section with a dummy load. Of course, if the first thing it does is explode, you know you had RIFA caps somewhere...
My experience told me I would have never figured that out. I have no tool that would have let me diagnose a zener diode failure like that of even to check it past the multimeter. I probably would have just slapped a resistor in there and left it at that.
@@coll6 either substitution or a series resistor and power supply to see what it breaks over at would easily tell you. I usually went with substitution, as I kept a shelf full of parts in stock for repairs.
hey Paul, while about an hour and a half of time, it was well worth my time. I had heard of a curve tracer, but never have I seen it put to work to solve a problem. what an incredible piece of equipment. and you built it yourself, sounds like I need to get on your patreon channel. thanks mike
Great Job Mr. Carlson, Oh the suspense of the last few seconds before you fired it up! Thank You!.......
My late father had a FT2000 it was an amazing piece of kit, he would of loved your channel. When I see you repair radios like this it brings back many happy memories of me listening to the radio with him in his shack. Thank you so much for sharing.
You're very welcome!
Clearly you and the subscribers are fans of tube based equipment, but I watch the solid state based vids. Thanks for posting this!
You bet!
studied for a few years, did the job for a few years, but this video made some things clear which i never quite got
Built the curve tracer. Ton of fun and a great learning experience. It's a great comparative tool. Fixed more than a few things quick with it. Paul's a genius.
Howdy! That is real interesting, I must admit. Could you please help a fellow and share the link to one you've made? Thank you.
That used to be a beginners project, with a complete discussion of theory of operation, back in the day.
If there's one thing I've never declined, it wasn't another drink, it was offered free training. :)
Mr. Carlson, it's nice that you repaired a fellow amateurs equipment.
73 P.S. Hope you and yours are safe from the fires.
I dislike getting someone else's kludge job into my shop for repair!
You did a great job straightening it out!
Incredible! I was just handling the same supply for my FT-990 that I extracted over a year ago after replacing a couple of caps and left it in despair due to its complexity and my boot camp level trouble shooting skills! I took a peek at at a few days ago and gave up again. You've given me fresh wind in my sails to give it a sporting try! Thank you so much Mr. Carlson, you are an emissary of God! Dennis - W4ZOR
Good on you Dennis. Go for that repair. I adore my 990s. Dont hear them so much now. But when you you do.......... The reports I have had. 73 de Mike.
The troubleshooting skills here are exemplary! Really outstanding work Paul. I enjoyed watching and I picked up several pointers. Thanks & 73.
I remember in school seeing an instructor do a demo on Zeener diodes, they call it the knee voltage at breakdown/ rated voltage. It gave a more intricate picture. Enjoying your video. We just pulled a ABB 520 amp 600 DC volt DC contactor out of a CNC machine. It puked. Well back to work, now in Valparaiso, Indiana. Hugh Mc.
I know this took forever with videoing and all. But it was REALLY helpful to see this process.
THANK YOU!!!
Outstanding troubleshooting video. Great analysis of the switch mode power supply and the technique of back feeding the 13.8VDC from the output to troubleshoot the output circuit and isolate the problem to the middle section of the supply. Nice use of the parts data sheets to obtain the starting voltage necessary for the IC to find out that it needed a minimum of 16VDC to start properly, which it did not have. Also fantastic demonstration of the use of a tracer scope to show the proper 'knee' of a diode whether it is a standard PN Junction diode or a Zener diode. Being a RF Communication-Electronics Instructor in the U.S. Marine Corps in the early 1980's teaching Basic Electricity, Basic Electronics, Radio Fundamentals, and Troubleshooting, I applaud your use of the current medium to be able to show your skills and experience on RUclips. Mr. Carlson congratulations on another successful repair demonstration. It is an honor to be a subscriber to your channel and providing you a thumbs up of every video I watch.
Thanks for your kind comment, and feedback too!
This one by Professor Paul Carlson a tough one. This shows Paul’s ability of electronic troubleshooting with
Correct disassembly and correct alignment in assembly with QC checks per step. Big dollar troubleshooting and repair
of a high dollar Ham Transceiver. Lot of information on using soldering iron and test equipment. Thank you Paul.
That zener diode leakage was one trap for young players! Well done Paul, thanks!
I have a curve tracer oscilloscope kit, which I rarely use. This video reminded me to use it more often. I certainly would have probably thought that Zener was fine.
Watching you repairing that PSU brings back memories of fixing 4kW SMPSU’s at my old company. Nobody else wanted to work on them. Takes a lot of caution and thinking outside the box, like breaking the loop, feeding external power to make sure the loop works, etc. so beautifully showed by you.👍👍👍
Thanks for your kind comment!
I already had a good idea on how switching PS worked but you just finalised my knowledge to a level that I am now pretty sure on how to debug them!! thanks!! proud to be a patreon user!
Great stuff. I think I learned about electronics in practice in a few of your videos more than I have in school in 4 years.
You're a wizard of the modern age! Thank you for another fantastic video!
Thank you very much for sharing this experience! I enjoyed every minute of it and learned a lot! I’m currently trying to repair a faulty HP 8591E Spectrum Analyzer. Your in-depth analysis provided a lot of insight on the methodology and techniques useful in repair of any complex circuit!
I volunteer as a repairman at the Repair Café: Quite common is the failure of switching power supplies in devices that our customers bring in for repair. In switching power supplies, troubleshooting is often difficult because the overall function results from the interaction of many components. If one component is faulty, the whole thing will not work. Isolating the fault is often difficult when everything depends on each other.
Thank you for pointing out that diodes and Zener diodes can also have leakage currents like capacitors. I did not know yet.
Also important is your hint in this video how important the correct position of switching wires in the devices are for avoiding unwanted electromagnetic interference.
THANK YOU VERY MUCH SIR CARLSON IT'S A PLEASURE TO WATCH YOUR VIDEOS YOU TEACH US A LOT AND YOU EXPLAIN IT SO WELL THAT IT EVEN MAKES YOU WANT TO REPAIR AN APPLIANCE LIKE YOU DO THANKS AND GREETINGS TO ALL YOUR FOLLOWERS 🎉🎉😊
You are very welcome!
Wow ! Someone is very fortunate to have you for a friend that could repair this great rig.
It was a real pleasure to watch such professional work with such excellent test equipment in expert hands. Great job finding the root of the problem! 👍🏻 It has been proven again that there are no poltergeists and curses in electronics, only bad components. 😁
Just a side note: instead of the curve tracer, if someone doesn't have one, you can use a laboratory power supply with current limiting and built-in ammeter, gradually increasing the voltage. If the resolution of the built-in ammeter is not enough, then you can connect the multimeter in the microammeter mode in series with the component under test. This is not so visual as the curve tracer, but it is also quite effective for finding leaking components.
Ex-sue-lent troubleshooting methods. You never shy away from big challenges to resuscitate NICE radios. Thanks again Paul !
That was just the type of troubleshooting I ve been waiting for! Excelente example of why I need to get myself a curve tracer! Thank you!
Mr Carlson, you are a genius! As one who used to repair electronic equipment, and also teach the subject at college, I can only admire your patience and ability to follow a logical course in tracking down faults. I was always very wary in attempting to repair switching mode PSUs especially as here in the UK the mains voltage is 230V so you might end up following a trail of damaged components! I loved your curve tracer with its ability to display the characteristics of components where a multi meter might not reveal a fault such as leakage. Just one small point. It would be useful to have a brief introduction to the principles of operation such as why SWPSUs have a high frequency oscillator which switches on and off a power output stage. Otherwise a superb lesson in fault-finding techniques.
This is a testament to knowing what the capabilities of your test equipment. It's too easy to forget the limitations of what is perceived as a simple diode check! Great perspective on troubleshooting as well as awareness of your gear.
Great work Paul! Love to see you work on more modern gear, especially ham radios.
That is a really nice dual band transceiver. It has been restored to perfection now by the true electronics wizard!
You are incredibly patient and competent. Thank you for taking me through your troubleshooting procedure.
I think we would be hard pushed to find many people with the knowledge and experience of Paul in the world of electronics.
Another excellent , informative video. Mr Carlson's self confidence is even more impressive than his skill. Nothing ever seems to baffle him.
AMATEUR WORKING ON IT WOULD BE CORRECT MR CARLSON. IM AN AMATEUR AND I WOULD NOT DREAM OF PLAYING AROUND WITH SUCH A SOPHISTICATED RADIO. NICE ONE AS AWAYS
Thanks for doing a switch mode power supply and ham radio repair. I like these longer videos as well as your short ones. Take care.
An avid long time hobbiest follower and listener from the Philippines🇵🇭😊😊😊 I just want to thank you Sir for sharing your knowledge and giving some insites lectures and tips for free about the intricate wisdom in the world of electronics. I really enjoyed watching your videos about restorations and repairs you've had made. Again, thanks a lot Sir😊 mabuhay🎉
My pleasure!
Great presentation. This retired R&D bench tech/PCB designer is still learning.
Very good description on the fault finding and repair of this strange fault! The leaking zener, which required curve tracing to reveal, is interesting! Also, good tip to reverse feed the o/p to confirm FB circuits are ok. I have repaired and struggled with many switching power supplies and know they are "beasts" when they don't work, so this is very good info, Paul!
Nice troubleshooting! Especially with the leaky zener.
Wow, another awesome video, Mr. Carlson. Despite my rather meager knowledge of electronics, I love watching these videos. Years ago I worked in a VCR repair shop, so I have some knowledge, but again, it's minimal, as I worked mostly at the front. I know a good, OK great, troubleshooter when I see one. I don't think a lot of techs could have figured that out, nor would they have the great equipment to test. Your skills and knowledge are astounding. That curve meter (?) to check the diode leakage was amazing. Thanks for the trip through the circuitry, etc. Most excellent content. Cheers.
Thankyou Paul i learned alot for trouble shooting switch mode power supplys as i have a few in equipment i own...no problems yet but as you know its only a matter of time thanks again ...termiteaudio
Thanks for the video, a wonderful demonstration of diagnostics and a beautiful proof that the diode tester can't find everything. I can't imagine my workplace without a curve tracker, I have been confirmed several times with similar partial damage to the diodes. The last such damage happened due to the degradation of the glue used to fix the parts.
Nice day 🙂 Tom
Great troubleshooting, tricky problem. Well explained. Most of beginners wouldn't be able to figure out leaky diode. I think you immediately knew where is the problem (from experience), but the video is prolonged for educational purpose.
Simply brilliant...I never cease to be amazed by your knowledge and talent...thanks for your efforts
This guy is so far up the electronics ladder his knowledge is way ahead of any one , with NO Dis respect to the other people
Thank you for this video. I learned a lot. I also want to thank you for the effort you put in to the camera position and the audio.
You're very welcome!
Great work Paul, I’ve seen most of your videos and I have to say I enjoyed this one very very much.
Many thanks!
Just THANK YOU so much for letting us to see everything from beginning to the end!
You are so welcome!
Incredible stuff Mr Carlson (Paul) what i leant today is when testing zener diode's, not to rely on a simple multimeter reading, ie closed or open circuit depending on the orientation of the probe leads. and how your modified oscilloscope showed a completely different picture, and well done
You got it!
Another masterpiece video Mr. C. You really make everything look too easy but thanks for this amazing venture.
Very nice troubleshooting and repair! Thanks, Paul.
hey Paul, a good way to remove epoxy is with heat, most epoxy with soften. mike
Thank you Paul.
I was once again allowed to travel along in a fascinating story.
73 pe1krx
Awesome as Always.. Wow what a mess Pleasure to watch and learn..
thorough, well thought out test and repair functions. Thanks again, Paul. You're a great YT contributor.
Thank you kindly!
this was a great video Mr. Carlson. I used to own a Yaesu FT 101- EE back in my Ham SSB radio days.
Mr Carlson I have had switch mode power supplies not only eating my lunch but my dinner too! This was yet another outstanding video and now back to getting my "glow in the dark" Hammarlund HQ180A back in service that I have had since 1970 something.
I wish you would produce more videos on more recent equipment. Your structured approach to troubleshooting is extremely educational for me. There are very few people here producing content on that level.
Amen
That's a great troubleshooting video Paul. It really shows that a schematic and a curve tracer can go a long way in fault finding. You can never fully trust your multimeter when it comes to checking diodes. One of the first tools I aquired when I retired was a B&K 501a curve tracer. It's a great tool for characterizing transistors and zener diodes. I suspect, although you didn't show it, is that your curve tracer can be calibrated so that you can actually see the reverse Vz of the diode under test. Even so a curve tracer is great for fault finding or matching transistors. And yes I always seem to learn something from your videos....
Today I learned about leaky diodes! I continue to be amazed at your knowledge and experience.
Been working on gear for years, yet learn soooo much from each of your videos. Please return to the boatanchor shoot out.
Tom
Great Paul and this proves you would not of found the problem with normal equipment unless you just happened to replace those diodes with new ones. Very good video!
Anotherbexcellent job done, Paul. Congrats! 👏👏👏👏👏👏👏👏👏👏👏👏👏👏👏👏👏👏👏👏👏👏
Thanks. I'm stunned at everyone of your videos. I'll admit, I have a long way to go before I'd ever touch that power supply. I have to chuckle that your leads and temporary connections hinder you the same as me. We emphasize ohms law but to add Murphy's law and you are so right.
I love your setup! It's so professional and warm at the same time. I also really like the topic. I've struggled to fix SMPS's for a long time. I'm getting better. Your two Videos on this subject are the main reason why.
Thanks for your feedback Walt!
A great video Paul, your explanation of switch mode diagnostics is next level.
Thank You !
Glad it was helpful!
Mrister Carlsons lab you are good at restoring vintage shortwave receivers and alignment of vintage shortwave receivers my friend 😅😅😅
As always, 'fixed the problem & improved the design just a tad while I was in there...' :-) So much fun to watch, thank you!!
You are so welcome!
Thanks so much for the video. Excellent to see an experienced tech reveal new knowledge! I have to admit the meter measurements would have fooled me. Today I learned something new. Now I have to go build a curve tracer🏃
Great video as always, Paul! I would love to know why the trick to test the Darlington transistor works (the initial dim light), and how you know to test for ESR vs leakage? Maybe a couple short videos on those tricks of the trade?
One thing about using a curve tracer such as a Huntron, for example, is KNOWING what a good component should look like.
I have repaired a LOT of things just using my Huntron Tracker, as it saves me lots of time. Switchers are FUN!!! Especially if you CAN'T get a schematic!
Very thorough and informative. Paul, thank you. 👍 Your work inspires me to open the supply on a Mark V field I own, and determine if I can add that fourth filter capacitor.
WoW quel beau travail de patience et de minutie 👍
Paul years ago we used a ohmmeter to test diodes & transistors.
this radio has a dc socket at the back. I had removed the switching supply, saved the money for repair and would feed it with a big lifepo battery. Thanks for the video!
Paul, have you considered renaming your channel to The Joy of Electronics with Mr. Carlson? I ask because you are most certainly the Bob Ross of electronics. Your ability to speak calmly while methodically explaining each troubleshooting and repair step in great detail is inspiring.
Thank you for another great video.
Now that sounds logical…. Lol
I find his voice so shooting and relaxing that is actually therapeutical for me. My down trobleshootings are a lot more frustrating, usually!
Well done Paul. This one was a hard one! Someone had released all the Magic Smoke that thing had in stock and more haha. Nice FT-1000. Only other high quality videos about repairing these transceivers that i can remember are made by the Brazilian Electronic Engineer Ivo Muniz in his RUclips channel with the same name.
73
73
Fabulous video Paul. I have not read all of the 'comments', however I'm sure we have all struggled with 'switch mode power supplies' and the troubleshooting of them.
Brought to you by "Blammo Electronics..!" LOL.. Love the tong ESR meter BTW.. very handy.
Great work Paul! Just replace that zener diode , after so many resets has dry out its main functions . Coping with that start up current . A source meter would be handy now .
You know your businesses , very Well !!! I haven't watch you for a very good wile !! I forgot how good you Are !!! God bless!!
Welcome back!
You put a lot of time and dedication into your videos, Thank You! 🙂
I never, never ever thought that kind of malfuction could exist! Tank you very much!
Thank you for teaching us about that most strange of devices,,, the switch mode power supply,, I learned a ton about the theory of operation,, :-)
wow what a great video, your methodical way of working your way through the problems is amazing, more of this please.
Every man must have a curve tracer👌🤟
At 1:04:00 the 21 volt measured is not the startup voltage but the regulated voltage from the backfeed because the power supply was working at that point. You could have traced the startup voltage during power on time on a oscilloscope.
Gosh darn it Mr. Carlson, thank you for getting me into ham radio again and making me want to get my license. I love all of your repair videos on radio transcievers.
Oh helll yes. Multiple failure and loooonnng video. The best!
A big G'day from Australia Paul and once again, thanks for another great rebuild.
My pleasure
Awesome repair ! I do like complicated stuff diagnosed well....cheers.
Reminds me of those old Panasonic VCR SMPS' with the 1uf 'bootstrap' capacitor that would dry-up, so the oscillator wouldn't get that initial kick ..usually right after a power cut! Lots of similar Zener and irksome output regulator issues in those, as well. Hours of fun! :)