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- Опубликовано: 7 сен 2024
- Smoke in the EEVblog Lab!
What component failed and caught alight in the RD Tech DPS5020 Power Supply Module?
This was supposed to be a build video and review until it caught on fire!
Follow-up repair video: • EEVblog #1036 - PSU Fi...
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Aha, the classic rubber glove over the smoke detector trick. Very handy when things emit smoke unexpectedly.
bigclivedotcom ... said Clive packing a pair of rubber gloves in his case for the next business trip...
Ladyfolk with expensive hairdos.
whin will you burn somthing out in a exiting maner?
I'm surprised you chaps haven't wired a bypass switch on the smoke alarms.
*bigclivedotcom* Hey Clive, I don't know why I am surprised to see you here but I am.
Damn! Sending a product for review and it goes up in smoke on camera. That must be a terrible feeling.
Happened to both Keysight and Extech. It's a wonder people still send me stuff...
*bigclivedotcom* Of course, if YOU were the one receiving the product, it wouldn't matter what company sent you something, you would always find a way to blow it up
EEVblog
we test it at at least 4 times again before sending , because the capacitor was damged in installation
he did not say that it was necessarily your fault :)
On the other hand it will be a great example of how the manufacturer/supplier handles issues like this. Which is as important as the design of the product itself.
i saw the video carefully. yes, the capacitor on output was burnt . it is high frequency filter capacitor. the data is withstand voltage 250V, 1210 packing , 104 capacity.
From our experience, the capacity should be compressed and deformed by external force. when you screw the output. the capacitore should be compressed.
so the capacitor place is not good. it was easily be deformed by exteranl force, I sorry for this
I saw you replace other capacitor, right ? in fact, you don't need add this
and I saw it still restarted and there is some current . because there is some shorted in burnt place , you should clean all the black burnt things up. because those black things can cause shorted.
you can use a knife to clean up them all . after this, it still can work normally. this capacitor is not important ...
you can try ..
the place is not good, I admite it this caopacitor defect is the crack resistance is not good, so the place is not good now our engineer are designing new way, new place and new capaciotor to solve this risk ... in fact, don't use the capacitor, it still can work normally
because only DPS5020 has this capacitor and only when the capacitor was damaged , it can be burnt,. ok? if some customer have weld station, they can contact me , I can send him a strong capacitor. I don't think this is a bad news , because all electric products are not profect. although the capacitor is easily to be damaged by external force, it soldem has happened. we sold thousands of this product, we only meet this at second times and this video can encourage to slove the problem to be perfect ... we should be updated tomorrow . after today, all the DPS5020 has new capacitor and even you don't need this capacitor, it can work normally, only the ripple will be small bigger than now
The world awaits take-2 of this review.
ok, I explain the reason and we are updating ..
Sounds completely valid, I was disappointed that Dave didn't test the output to make sure it wasn't still shorted from all the charred fiberglass too. Maybe he'll do a follow-up on this since it really looks like the board is fine aside from the burnt portion that's most likely causing the output load.
If that supply was used to power something like another SMPS or a PWM based device, it seems to me the high frequency current pulses would thermally stress that cap also.. I know he had no load on it when it happened but what had he used it for previously?
Thanks for responding Glen, glad to see it's going to get fixed.
A chunky 55V PSU isn't much different to an arc welder...
An arc welder is just a really chunky 40-80V PSU
You could even use 4 car batteries to make a cheap 48V welder.
Wouldn't that be an expensive single use 48v welder or do the battery's actually survive?
A welder is actually a constant voltage/constant current psu. It need an highish voltage to maintain the arc, specially to start the arc. Once the arc is going, you will get only a few volts, like 10-20V, but can be quite some high amperage.
My FM transmitter uses welding cables to move current to the PA.
that was a classic eevblog episode, highly entertaining.
The carbonized area of the PCB is probably working as a resistor between the output pads now.
Or rather as a conductor.
Yep that was what I thought immediately, I have fried up some boards on my channel and with only 13.8v I got flames and arcs through the PCB itself
jh77sly yeah Dave should scratch it away a bit and it should work again
Dremel it out with a burr and epoxy coat it.
Forget that part of the PCB, it's gone, dremel it out completely. Scratch away at the traces where it isn't burnt to attach new leads.
11:09 Dave, there is still a tiny layer of metallized vapor all across the pins. It's not a perfect short, but it may draw a little current.
there's also a new carbon resistor embedded in the PCB
@@randomblogger2835 I thought I repaired a washing machine power supply once. It worked well for 2 loads, then let even more magic smoke out. I figured it could be the copious amounts of carbon now lying around 240v, or equally, WTF would you route the outlet hose pressurised by a pump, right above a SMPS? Dingbats.
just order some replacement magic smoke and put it back in, no worries
The video itself made me laugh so hard... and than enters this comment... :D
@@TheTinkerDad Well, you know those weird funnel things that come on the end of new meter probes. Those are complimentary magic smoke funnels!
I'm a quality provider of magic smoke. Give me some components and a few kilowatts and I'll make enough magic smoke to make Pablo Escobar jealous.
lmao
Dave this type of video is why, in my opinion, you set the standard. It's like a conversation with a personable and highly knowledgeable colleague discussing a topic - straightforward, not driven by an agenda and honest about what you know and what you are assuming. As an Electronics Engineering student I find every one of your videos a helpful addendum to my coursework.
Thanks.
I really like the fact @Rd Tech take the time to address every question. Even when I ordered mine (months ago), th asked me if I liked the product and if there is something they should fix. At first I thought it was an automated message. I took the time to comment on some improvements that could be made, and they immediately answered back, that they will try it.
Only wish his English is better but he's still better than most Chinese. What a great manufacturer.
thank you for your message and your support
quality is our life,. I need to know all the details of the product user, the customer is my god, if they have any question, they can answer me , I can help them , it is our responsibility.
thank you again
@IRFZ44
thank you , I will improve it ...
RDTech is fantastic. I have a couple of their power supplies (RD6006 and RD6012) and they have been reliable and feature rich at a great price. With the free app and wireless interface, they can even do complex multi-step voltage programs easily. RDTech have continued developing the firmware over time, improving the visual appearance of the display. Just a great product I recommend. To be fair, I was careful when I put mine together and never considered it a test of my strength…
Es el mejor servicio al cliente q e visto, llevo 6 años consultandole y nunca dejo de responder.
I love that intro animation in the bottom right corner!
Me too!
+1
I HATE IT BECAUSE I MUST BE THE ETERNAL CONTRARIAN! :P
No you're not.
The TQFP chip has 2 pins shorted??? 18:10
Good eye!
Probably just a clothing fibre but worth checking out.
Almost looks like a deliberate bridge.
rorroparo
I saw that place , it should be solder splash, I guss Dave drop it mistakely when he install the case , but there is nothing with the board, it control the display . this is not from our factory, because this chip was weld STM machine, it is impossible that there is the solder splash on 2 legs. we don't weld the chip by hand..
Rd Tech "big" chip next to C16, upper left corner of it.
My guess why the Capacitor burned ist the following:
When you screw the wires (especially the black one) you bend the PCB quite a lot. This breaks the Ceramic-Capacitor. The multiple layers of the broken Capacitor form a short circuit with some ohms. This burns quite well when voltage is applied. I think it would already help to turn the Cap by 90 Degrees or/and shift it to a place where less bending happens.
Coolest ceiling decoration ever!
Just remember to take it off before Health and Safety comes around, or you'll be emitting smoke from several holes on your body :-D
That burnt board is probably conductive, which would leave you with a short until you clean it all out.
True, but it really shouldn't be resetting itself even if there's a low load on the output, the module is current limited. I think there's a deeper problem.
yes, you are right , there are many protection on the board, just clean up the shorted things, it will be ok
Hes current limiting on the input supply which is why I think it was rebooting. When the current limit is reached it will reduce the voltage which results in the module wanting even more current etc etc until the voltage gets so low the module crashes.
@Clyne Griffon
Yeah, you're right.
@Clyne Griffon
it still caused by shorted on the output .. ,. just clear the burnted things
the place is not good, I admite it this caopacitor defect is the crack resistance is not good, so the place is not good now our engineer are designing new way, new place and new capaciotor to solve this risk ... in fact, don't use the capacitor, it still can work normally
Failures like this happen. You can make everything perfect but then your supplier has delivered faulty components that will burst in flames. That is why I always recommend to use a non-flammable case like the one shown in the video. It has safely contained the fault, nothing but a bit of stinky smoke and no further damage.
Unfortunately I have already seen the works of some people that were built on a piece of cardboard. A circuit to switch a 12V/40A load via rs232, it was just a relais, a diode, a transistor and a few resistors all glued with packaging tape on a piece of cardboard, covered with another piece of cardboard and installed into a computer. No fuses, no non-flamable containment (the metal case of the computer had some holes for the cables). But luckily it worked until it was removed without the house burning down. ;)
AniMageNeBy Es gibt auch noch eine andere Variante. Einfach in der Muttersprache schreiben und damit die Leser zwingen Google-Translate zu benutzen. Manchmal führt das zu besseren Ergebnissen als die Versuche in einer fremden Sprache zu schreiben. Aber das Englisch von Rd Tech war für mich einfacher zu lesen als das was bei manchen automatischen Übersetzungen heraus kommt. ;-)
Well, yes, maybe you should. Though I imagine it won't be easy for everyone to understand you, and let's face it: google translate (still) sucks, even though it's slowly getting better.
That said, English is the international language these days, so it wouldn't be bad if everyone could use it. Speaking/writing shouldn't be too much of a problem (I'm not a native English speaker neither, but I'm doing alright, even if I say so myself ;-)). But IF you decide to write it, you can easily use a spellchecker; it helps a lot in the details or if one has been a bit too hasty. There is also no problem to install several of them (in fact, I have 3 different languages).
German is not one of them, but I can understand it just fine without any translator, though granted my passive knowledge (understanding/reading it) is much greater than my active use (writing) of it, so prefer to speak in English. But, if you want to speak only to me, feel free to speak German, I have no problem with it - I don't need google translate ;-). My point was merely that, IF one does decide to speak another language, it's worthwhile having and using a spellchecker of it as well.
PS. the link was actually meant for Rd Tech, since he made a whole bunch of obvious spelling mistakes and was, indeed, difficult to understand (though granted, more through his grammar construction than through his spelling). And I do not know what his natural language is, so it might even be Chinese. But I think it's better everyone tries to speak a common language, than everyone speaking his own language and let crappy translation handle things. But either way, it doesn't inhibit the use of a spellchecker.
Rd Tech
You need to relax a bit, your products are ok they just need some fine tuning like any new product .
AniMageNeBy Rd Tech is the RUclips account of the vendor of the PSU. They are in China and their primary language is probably Chinese. Automatic translation tools tend to fail horribly with that language. I normally have a better chance to understand badly written English than the result of some automatic translator.
When you pasted that URL it looked like a lazy way to say that his English is bad and that is why I responded like this. His English was understandable for me. Maybe because I used the context of the video to analyze his text. Anyways, I have seen much worse English in some user manuals from China and his English was better than this!
And yes, I absolutely agree with you about English as the international language. Nearly everybody understands it and it allows communication with people all around the world. And that Link was also helpful for me, because until now I had red squiggly lines under every English text I wrote and now they are gone. I didn't know that Chromium (Chrome fork) supports multiple languages at the same time. ;)
With that much charring, it's no wonder it still fails. I guess you will have to take the Dremel out and cut an isolation slot between the terminals.
Yes, this. I bet there is a low resistance path between the terminals.
yes, just clean up the burnt thing, that's ok
I'm somewhat surprised Dave didn't know or comment about this.. So many of us have charred PCB:s and had to use drill/file/dremel. Perhaps he could to the followup.video on this?
Mine was back on 386/486 days.. Who knew that those ** expensive VGA Graphics cards might have unfused +5V power output at the D-15 connector. One bent pin and one quite crispy PCB. Recoverable, but definitely not pretty. But hey, it worked for some years. :-)
Be a pal Glen, post the schematic. Most people are more likely to buy a product that they know can be repaired, even after a fire. Your sales will skyrocket! It’s not like we can built one any cheaper than you anyway, just the parts would be more than $20!
The Combat Engineer The problem isn't us. It's all his local competitors in the Hong Kong suburbs (aka Schenzen).
I think that’s spot on.
Agree, $20 bucks for a very nice looking power supply - I thought he meant $20 for the case and external parts, that the power supply would be additional. I've looked at these kinds of power supplies through bangood but didn't trust them. Combat engineer, great name, I served with a combat engineer unit 2004-05 in Iraq. I have a lot of respect for those combat engineers. When thinking of this experience I though EVVblog was going to need to don his bomb suit, get out the demo robot and blow the thing up. The reality of building stuff is experiencing the joy of magic smoke. Sad to say I have installed a few parts backward or reversed my transistor looking from the bottom rather than the top. I think that is why you always buy a bag of transistors. Had a power surge go through my house this summer and it took out just about every switch mode power supply, magic smoke everywhere. House full of guest, TV smoking, the kids pointing ever which direction saying they heard a bang over here and over there. I ran and hit the main breaker then set about to determine the cause. Our cable had gone out and the cable man was fixing the cable when he disconnected the cable we lost the ground path for the severely out of balance load. The US uses a two live wires180 degrees out of phase with a neutral line to carry the difference in an unbalanced load. and if all fails a ground to earth ground. The neutral line had been chewed off by the squirrels, the house was using the ground to take the difference, 80 volts on one line, 140 or 180 on the other line, and that little coax cable was carrying a lot of the ground for the house load. I think the cable guy is a believer in those safety classes now. that high voltage and a lot of currents can be finding a path through their equipment. His eyes got as big as saucers when that thing sparked, he was shaking for 10 minutes. he had his work gloves on, I had warned him of a power problem that the previous cable guy said was happening in the area. The power company said they couldn't do anything about it, it was an act of nature. I would think that the expectation is to receive a proper supply voltage with the correct neutral. Well, it gave me a chance to change a bunch of little weird fuses, and thermistors. Surprisingly that is the only thing that blew. Able to get parts off of some old boards so it didn't cost anything to fix. I did through one LED light fixture away, I didn't even try to dig through all the epoxy and tiny parts. My old analog pinball machine dimed the lights and blew a fuse but nothing was harmed a fuse in the right place. The other pinball machine did not have any impact.
I built one using a DPS3012, a 24v 15amp power supply, and a 1200watt boost converter. Out of all the DIY or China built power supplies it is the most stable and true. I really like these little power supplies and hope to get me a 5020 soon. Great Video and I just subscribed!👍
Glad to hear you say that, my DPS3012 arrived a couple of days ago...
On 18:21 you can see a small blob of solder on microcontroller. Try to remove it.
I did not see it
yes
Wasn’t sure if it was a light flare thing at first, but it certainly does look as though there is a stray splash of solder bridging the top two pins on the left side of the micro controller.
At 10:23 no solder short.
So that one probably came from Dave's repair job. Or just a splash from when the cap burnt and it found it's way onto the board later by turning it over.
Yep, not there earlier. Any way that could be causing the weird readings Dave was getting later though?
My money is on the PCB being carbonised and thus forming a low-value resistance between the output lugs on that board. You'll have to cut away all the burnt board. Measure around there with an ohm-meter and you'll likely be surprised at how low the resistance is.
I did measure it and it was fine, hence the re-power test. But it's now a low value, so the re-power changed it's properties or some such.
@@EEVblog Ok, now i see. But if you measure charring resistance with an ohmmeter, there is no power involved, so nothing but megaohms to be expected. Charring isn't a stable situation you can work with. Not as an electrician at least. As soon as you fire the power up, the coal gets active. Maybe soaking with epoxy may help instead of coal removal, but i wouldn't try, because it's always to much at stake, so i don't know.
I love how you have a procedure to follow immediately upon something smoking itself.
I'd say that cap suffered chronic electron diarrhoea, basically it shat itself... :P
I saw these modules on ebay, and wondered if they had been designed properly, very busy and very complicated design PCB, and in no time something failed in smoke, excellent review.
no , it is not time proble , we can't damaged our capacitor to test . first , it is not capacitor quality problem , ok ? if you damaged any part by force, the power supply will burnt ...
in fact , the capacitor place is not good ,and this capacitor is not strong , easiy damaged by force
understand ?
Halt and Catch Fire, the reality show. Stinky!
I'm a little surprised that Dave is so nice to the manufacture given this major failure. I can't lost count how many time he has crapped on shoddy work, assembly and negatively commented on a product. I like the video, I wonder if hew ever did a full review of it as I have need for such a small supply and would love to have one with a nice display.
See my previous videos.
Glad to find so many known names here! :-D
Dave, Mike, BigClive! Who would want to miss Dave putting things to fire?
As an American viewer I am glad you wasted no time and got right to releasing the magic smoke.
A really bad place for that cap - Near the edge of the board and mechanical stress from the fat wire terminals fitted nearby.
Probably developed a micro-crack then failed short.
Should use a cap with polymer terminations in that environment.
Yeah, mech stress + thermal stress double whammy, not good.
If I buy one of these PSU modules (not necessarily the 50V one) I will make sure to unsolder that ceramic cap and fit a through hole ceramic or electrolytic instead in a better place. That is definitely not a good location for such a small fragile heat sensitive SMD cap.
Steven Birch
yes, you are right , this caopacitor defect is the crack resistance is not good, so the place is not good
now our engineer are designing new way, new place and new capaciotor to solve this risk ...
if fact, don't use the capacitor, it still can work normally
EEVblog
yes, the place is not good, I admite it
this caopacitor defect is the crack resistance is not good, so the place is not good now our engineer are designing new way, new place and new capaciotor to solve this risk ... if fact, don't use the capacitor, it still can work normally
Simon Tay
even you input more than 55V, you also can unsolder this capacitor, that's ok?
it is just filter capacitor.
Great video. Those are called "Electrosplosive Capacitors". It looks like the cap failed due to Thermal Expansion Rate differences from the Board and Terminal Blocks, and possibly mechanical stress from flexing the power cables - which flexed the board and thus the cap to crack and short. Notice how the PCB didn't catch fire but was charred? This is why this type of PCB is FR-4 (Flame Resistant Material 4) - a fiberglass and resin material that usually won't catch fire if a component on board does.
The designer of this power supply was not well versed in decoupling caps and inductance. Those Terminal Blocks have a lot of inductance, so SMT caps which generally have low inductance are less effective close to the terminals because of the inductance. I have used similar Terminal Blocks like this before, I used large through hole caps near the Terminals because noise is not a problem there, it is power sag as the load changes which is the issue there. 100uf caps with low ESR and a WVDC rating of twice the max voltage is the way to go. You can't get those high values and large WVDC in SMT Ceramic caps, so you have to go with large Tantalum caps that can handle the thermal, mechanical, and in-rush current. Decoupling for noise (where you do indeed use Cermaic SMT caps) is done at the noise source - like at the switching transistors and digital circuits - not at the power output where inductance from the power cables alone block a lot of the high speed noise. Put a choke around the power leads if you ever see high speed noise get through the power supply to the load, those tiny SMT caps were doing very little for noise or power sagging, and I bet their voltage rating was only about 10% higher of the expected voltage - not enough design margin for high current applications.
I had the same problem 15 years ago. This (apparently) happend randomly
only to the capacitor soldered by hand. The capacitor was for DC supply filtering too. I found that the problem was due to:
- the very high temperature of the solder tip,
- the relatively long time to solder due to copper pours,
Without preheating the PCB, there is a temperature gradient on it and once both sides of the capacitor are soldered, there is a mechanical stress that could make some internal cracks.
I guess the problem is not only o the carbon of the fiber glass. Once the capacitor has entered on 'avalanche' (internal layers shorting more and more) the current is not 'smooth', and the output voltage of the power supply (adding the leads inductance too) could generate transient voltages higher than the MOSFETs 80 V.
I appreciate the "intrinsic defect" and thermal stress notes... valuable bits and pieces of info
Why did you tease this video with flames? I wanted to see FIRE!
I assembled the same kit with the buck/boost version a few months ago, works great from my 12v solar system.
a latex glove over the smoke alarm... You're the smartest man I've ever freaking known
Life hack as they call it.
On holiday the wife complained the air-con went off when the patio door was opened... a fridge magnet and some blutack solved it... yeah, air-conning Earth's atmosphere really isn't going to work but it cleared the air of bloody moaning, that's a life hack ;)
"Love the smell of a bad power supply in the morning".
Best reference of the year.
Surely this time I can't argue with the fact that current was indeed flowing through a capacitor!! A shitton of current to be more precise ;)
the capacitor was damaged by force during installation. after the video we updated it , change the capacitor and place
I think the current is going through the burnt board. should test resistance then remove some of the burned board and see if the resistance goes down.
CrazyMonkeyCM32 thought the same, how didn't he try and scratch that
yes, those bunrt thing are shorted. just clean up that
Alexander Bukh
you can use a knife to clean those up
Mine just came in the mail today and I'm glad to say that they've improved their soldering skills and the pads for the defective capacitor are currently unpopulated, it looks as though they listened to your advice.
Use the (Flir) Thermal Cam to see where the short ciruit current flows?
That's may favorite tool for mystery rail shorts. My second is a high-count voltmeter with kelvin probes. Almost always either a fractured cap or a dendrite.
Watching this video months ago really paid off. Today one of the ceramic caps failed in my 3d printer, I was able to understand why and not panic amount the tiny fire happening on the stepper driver board.
this capacitor is easy damamged by force
Isn't there a big ugly solder bridge short across 2 pins of the 48 pin IC, visible at 18:11? Perhaps this could be a contributor to the problem?
I saw that place , it should be solder splash, I guess Dave drop it mistakenly when he install the case , but there is nothing with the board, it control the display . this is not from our factory, because this chip was weld STM machine, it is impossible that there is the solder splash on 2 legs. we don't weld the chip by hand.
My 5020 just arrived yesterday - first thing I did was remove that cap! :D
While it sucks yours went bang, it hopefully helped many others to not have there own do it as well.
your dps5020 still have old capacitor ? when you buy this ?
Dave you scared it to death That beefy one is just too much for the little guy
Hi, in other review of this thing on tube, was mentioned that if you want to use it with more than 30V you have to change this cap to more voltage. It was provided by manufacturer information...
Do you have a link to this information, please ?
lets admit that this unit is good , the R&D from chinese products works , at least for people that doesnt have 300$ for a bench power supply. chinese products are not trash anymore.
back at 90's or 00's i spent 2 weeks and 120$ to make a lab psu 0-30v 3a , was huge and expensive. consider how many kids and people can do amazing things with just 20$ , to make a small setup for fixing and learning electronics.
I just got this power supply through hobbyking. And the cap that blew is no longer there so it looks like the devices on market now are fixed. But if you do not need alot of Amps I recommend to buy the DPH5005 Note the H instead of S in the name, This device can boost your input voltage up so you do not need 55V input to get 50V out, you can get 50V from 12V input.
thank you so much for your message ,yes, we already fix it , and change the place and use strong capacitor
Well here is the repair you have been looking for :P
just clean up those burnt things, that's ok
Amazing amount of support from the supplier, I will try some RD tech products :)
Dave, it would be interesting to do a thermal image with the FLIR of the board when powered up. if it's really a conductive path between the output terminals, it should be possible to dremel out the burned pcb area inbetween. but maybe some of those mosfets (are they doing synchronous switching?) failed low resistance between drain and source.
The charring did indeed become conductive. Basically made a crude resistor.
+EEVblog new start and ending intro clips are just gorgeous to watch. Nicely done!
I may actually buy this unit - despite the fail in this vid. Just remove the bloody cap if the one i get shipped still has it. Yeah, would be a nice exercise to design a better one - but sheeeesh - tiiiime....gimme tiiiime.
I own one of these. A year or two ago, the tiny PCB-mounted output fuse blew while charging a 12V lead-acid battery with the power supply.
I'll have to have a look to see if mine has this faulty output capacitor design, and remove the cap before trying to replace the fuse.
I'll probably replace the fuse with a large, easy to replace type, as the wee PCB fuse is VERY much not "replacement-friendly".
Yess, popcorn time!!! Thanks
Proyectos LED maybe next video will be Dave making popcorn with the heat from exploding components.
I worked at a power supply company for 25 years - unregulated, linear, and switchmode. I started as a technician and plodded my way through engineering and management. Switch mode supplies are lightweight and compact BUT when something goes wrong you do get copious smoke and usually a little flame to go with it.
The engineering has to be just right and the parts quality has to be very good or they fill fail spectacularly. I have 4 power supplies on my workbench and everyone of them is a 40 year old linear supply made by old line companies. These can be had on ebay for very little money but it does cost a bit to ship these old boat anchors (a one KW supply will weigh more than 40 pounds). Replace the bulk caps and they go forever
My electrical engineering prof's line was.
"When you see smoke in the electrical lab your are just getting started. When you see smoke in the electronics lab you are just finishing."
Good video. An eye opener indeed into the world of capacitor failure modes and designing for reliability. Also, I like the outro.
The problem of the short circuit is due to the burning of the pcb, burning the pcb charred the substrate of the board, transforming the insulation material into conductor (carbon). I have had problems of this type, and the solution is to scrape the pcb to remove all the carbon from the burned region of the pcb.
Or cut out an isolation slot between the output terminals.
yes, you are right, just clean up those burnt those thing , that's ok
The latest versions are ok. The vulnerable cap is gone, and fan is quiet. Wonderful product.
Isn't the charred epoxy basically graphite and thus conductive? Try removing everything that's charred and short on the output will probably disappear.
I second this. Best to physically cut a slot in the board between the output terminals to remove any chance of a conductive path.
EEVblog
please scapt those to try
Dave: You need to clean all the charred PCB out from output side and then try again. That blackened material will conduct current and keep on burning more and more.
It could be recoverable but you'd need to do some destructive file/dremelwork and then refit the output cabling.
Release the *SHMOO*KE.
looks like it cheeched its last chooch
ANTHONY CABALLERO
Releasing the smoke is the easy bit, trying to put it back in is the hard bit.
vk3hau If you figure out how to do that, you'd make a fortune.
@@combrains1 Good eye, per Rossman, the fan isn't choochenging.
*SCHMO*KE.
Good thing someone told Dave to cover the smoke alarm ...thought he was talking to his assistant at first lol
Lot of carbon scoring here. Looks like you boys have seen a lot of action.
With all we've been through, sometimes I'm amazed we're in as good condition as we are !
the short cut is just that burn in the fiber-glass pcb, that acts as a huge resistor on medium voltage.
The charred pcb is probably now conductive charcoal... or rather char epoxy ;-)
Man, your neighbors must loooove you!
From about 8:37 If you have 2 equal value caps in series, and one shorts out. Wouldn't it double the capacitance in that part of the circuit? Woudln't it just be like having one cap.
yes, you are right. in series, it will avoid this problem, but this capacitot and place are not good, we are updating
Yes, but the point Dave is making is you won't have a destructive short like in this video, because one cap is still good. The chances of both caps shorting at the same time is extremely small.
Yeah, but Dave said it would halve the capacitance when one shorted. It would actually double it. But Dave knows that, he was probably just loopy from the cap fumes.
Hyxtryx I thought he said it would halve the capacity under normal (nothing shorted) operation, which it would.
It would, but why would anybody do that? If it calls for a 100nf cap, and you want to take advantage of this "trick" (I'll call it), you wouldn't put 2 100nf caps in series, because you'd be left with 50nf during normal operation. You'd use 2 200nf caps to give you the 100nf capacitance the circuit called for. Then if one shorted you'd wind up with 200nf. Dave didn't spell it out completely, but I knew that's what he must have meant.
The burnt carbon that you didn't remove from the board is probably creating a resistance between your output points applying a load even when you have no external load attached.
yes, he did not clean them all, there are still shorted
Nice thumbnail, but you forgot the red circle and red arrow.
What about the red hot knife with blow torches? (Glad that shit died off quickly)
The title should be *"EXPLODING POWER SUPPLY, NEARLY CATCH MY HOUSE ON FIRE!! (GONE WRONG, ALMOST DIED) // 200 FIDGET SPINNERS GIVEAWAY + RED HOT KNIFE VIDEOS AT THE END!!"*
You did a teardown of that Xantrex CPU on #268. FIVE whopping years ago...time flies.
Damn.
16:34 How effective that heatsink is going to be when placed on the wrong side of the transistors? Plastic is not really thermally conductive, so is this heatsink going to actually be able to absorb any reasonable amount of heat from the MOSFETs?
I thought the same thing!
Surprisingly yes. One of the strange things about insulation is the surface area increase of the overall part outweighs the thermal resistance due to thickness up to a point. Those fets will get significantly hot on the plastic side allowing for reasonable heat (thermal energy) removal.
but the heat is produced on the metal tab so only radiated heat will be dissipated, i think...
No, heat is also transfered in the insulated front, just not as efficiently.
anyway I would not rely on this type of heatsink ;)
If you place 2 capacitors in series for this reason, don't place them in the same direction. Have a 90 degree angle between them to minimize the risk that both crack if the board is stressed in one direction.
it is not useful for this , i have use stronger capacitor to replace it , that's ok
8:35 actually capacitance is doubled when that happens :)
Did I say halve? oops.
Capacitance does not _double_ in series.
Good to know I wasn't the only one who have a unit break. I bought a DPS5015, and case. Started it without a load and and turned on the output... Dead.
He sent me a pack of transistors
18:09 solder blob
I think due to the fact the ceramic capaitor was directly soldered to the terminal pins it suffered from mechanical stress while attaching the wires to the terminals, so there might have been a crack inside the capacitor which led to the short circuit situation
yes, you are right
I have used stronger capacitor
Dave is proud of his 1000W PSU that grilled the cheap supply ... BUT its >1000W at the high voltage. Since its only 4A. Its output capacitance is not going to be that high otherwise it couldnt current limit properly. Funny.
Still 220W capable at 55V
you are totally wrong ... this is not the reason ..
because the capacitor place is not good, it was damaged by external force, so it was shorted after power on
Rule 1 for trouble shooting burnt electronics - look for skidmarks on the casing.
There appears to be a solder short between two pins on the 48 pin chip seen in the video at 18:13 ruclips.net/video/Q2rvAoO-MIA/видео.htmlm13s
I wonder if that was there in the previous video or if that extra solder was splashed later on?
I saw that place , it should be solder splash, I guess Dave drop it mistakenly when he install the case , but there is nothing with the board, it control the display . this is not from our factory, because this chip was weld STM machine, it is impossible that there is the solder splash on 2 legs. we don't weld the chip by hand.
What does PA3 (I/O pin 17) do in your design ? The one shorted by the solder flashing to VSS_3 (GND) on pin 18 (ps- I misread your statement above initially. I understand what you meant now.)
Mechanical stress fractured the multi layer ceramic and allowed layers to misalign to the point it becomes a dead short. This makes a very hot similar to arc welding.
yes, you are right
That's very promising PSU but cooling is SHIT.
I would see there cooling similar to that from the laptops with heat pipe and blower style fan.
When it was designed and tested this fan was installed on top of the mosfets just to bring their temp down to a comfortable level at full power since it obviously was seen necessary to keep a good lifetime out of it and they did the trick by this simple and easy way. Even if this type of cooling mounting is not the most efficient to cool a package like these mosfet its absolutely better then nothing and was also tested to be enough so I have no really problems with it as long as it works.
I have a DPS5015 and also went black!!!!
Simply when I was testing a simple and tiny DC motor with 3V!!!
Does not even turn on anymore!
the schematics of these boards would be very helpful to repair them.
12:05 "JET FUEL DOESN'T MELT STEEL BEAMS!" No but exploding capacitors do...
Easy to tell where you've been on the web.
Just in case.... Jet fuel doesn't need to melt steel beams. It only needs to weaken it to below the design specs, and gravity will do the rest.
Oh hell, the 'Conspiracy Theorists' have arrived, Yawn!
But there is no way that a crashed 737 made those markings in the Pentagon!!!
I'm joking of course, just like everyone above is. So don't worry CoolKeys, I don't think any of the nutters are here. They all sodded off one they saw Dave's solar roadways videos.
and building 7? haha
8:40 -> small error there; if one capacitor fails you actualy get twice the eq.series capacitance
If the one fails to a short ---you're right. Good catch!
Becauce the cap shorted out.
And you loose half the operating voltage. Two 63V in series can handle 120V, if one dies short you only have 63V capability.
You put flames intentionally over the thumbnails of this video...
Please don't be scummy with clickbait...
Burn marks can be conductive very good... I think this is the reason why it draws current without a load connected and shuts down when the output is enabled.
You should really contact the manufacturer before putting out such a video. This could ruin their business.
Manufacturer is RdTech, on this board now, conducting damage control.
the manufacturer had to test it more vigurousely, maybe they're going to make their tests better now. They expected free publicity, now they probably learned a good lesson, murphy is always where you don't expect
No, that's not how it works. You send your product and you take your chances. Stuff from Keysight, Extech and others have failed on camera, no one gets special treatment.
Engineers know "shit happens", it's a how company responds that matters. The fact that Glen is on here admitting it and saying it'll be fixed will grow his business rep, not ruin it.
What a nice discussion here. I like it.
Generally a very good signal-to-noise ratio in the comments on this channel, especially when Dave himself puts in a reply. :)
Nice sound at the end of the video, if you listen to it with headphones, it goes from one ear to the other.
Now I know my unit wasn't a just a bad batch... Too high failure rate on these units.
These are absolute junk....
First off I would like to state that I am not nearly as qualified as most when it comes to electronics engineering and circuitry . With that said, I'm sorry for may apparent harsh comment. I just happen to notice that Mr. Jones had uploaded a campfire video and so thought I could sing along or help carry firewood. I purchased two of these units a few months ago for a small project and one of them went "poof" are maybe "pop" fairly quickly (in a week or something) Thankfully they're not too awful expensive so I wrote it off as "eh, whatever.... no biggie, waste of money for a toy but they are kind of a fire hazard". As far having failure rate data, I can only compare my two units and Mr. Jones' unit (that would be awkward, I've heard Dave's .... never mind....) Not being totally comfortable with my public school education I decided to go upstairs and ask my Mom and she grounded me for watching porn again! So I "googled" failure rate calculations and can up with a MTBF of 15.5hrs, assuming Mr. Jones failed unit survived 24 continuous hrs + 3 hrs on my 1st failed unit + 5 hrs (so far ) on the 2nd surviving unit. Since the Pi calculator is still going and I can't find my lighter , I'm gonna go with 66% give or take 1% in unused kindling just shy of the apparent 70% required for scrutiny. With that I leave you with my respectful retraction of my first off the cuff comment , but as a consumer I wouldn't buy another "work in progress/fire hazard" beta project. Just my opinion.
too high ? there is data to agree with it
Funny how you always seem to hear about people with units with failures, you never hear about people complaining that their units work.
A few bad units doesn't mean that the whole line of product is crap, unless you have data that over 70% of total units fail, you can't say they are crap, sorry but try again.
Output is still shorted. Carbon is conductive. You've gotta cut/grind all that stuff out of there until you have bare fiberglass.
Dave, smdh, you filmed yourself covering a smoke alarm in a shared office environment and then published the video for the world to see?
Understand your concern but i think it's maybe a bit harsh.
I'm all for safety, but the situation was clearly under control, and who knows what the cost of a fire response is for the office alarm, plus the inconvenience for neighbours.
Under the circumstances could you see it from the other side of the coin?
I've thought the exact same thing. I know that doing that is illegal in some countries.
Even if it's not illegal, it may not be something the building owner would want to see from their tenants. If the building happens to catch fire later, another tenant might sue the owner ~ "You had clear evidence that your other tenant was covering up the smoke alarm, and you did nothing to prevent this!"
Please provide Dave your address so he can send you the bill the next time it happens :P
Nothing worse than a bureaucrat. Got an iron rod up ur ass following every rule to the letter no matter how illogical, unnecessary and annoying as hell it is. Triggggeerrrred hahaha. Ok i'm good. (They're robots, Morty!)
I think the rebooting was caused by current limitation set on the lab psu. As the device was powered on the terminal were cold. Dave set a voltage and current that exceeded what the lab psu would deliver with its settings at that moment. In that case the voltage from the lab psu dropped below the minimum voltage that the other device needed to operate. As soon as the micro controler threw its hands in the air the terminal where powered down and the supply voltage sprang back to a level where the uC could operate again.
My guess is that the terminals were still shorted, maybe bits of the charred PCB became conductive.
Fairly easy to repair.
yes, it is easiy to fix , he just remove the burnt things, that's ok
Haha, I just did fire warden training yesterday in Sydney and they said it's $1700 if the Fire Brigade is called out. Rubber gloves was not discussed during the training. :)
Yep, I knew a few people in the building who have had to pay it.
Could be/looks like from the old picture, that the C has been handsoldered. That might have caused mechanical stress, which decreases the „time to smoke“ rate.
at 18:10 in the video, you can see a short on the 48 pin leaded chip below the screwdriver in the corner of the chip. Looks like a fine piece of stray wire shorting out two pins!
Watched the last review. Added the power supply to my shopping basket. Didn't click checkout. Decided to look around for more reviews. Then watched this video. Removed the item from the basket. Will be bringing my full scale lab power supply out of retirement instead.
These are fine as long as you don't use them at 100% input/output spec. I use mine with 36V in and 5-6A max and they are great and run cool at those loads.
Hi friend
don't worry
about this , I just explain this , the capacitor was compreessed by force. so it was shorted. now we are updating and choose a new place
Thanks for looking into this. I often go with Dave's recommendations when making purchases. If he does another positive review, I might reconsider. I've also had similar failures with caps in devices that I sometimes service. Fused caps, especially the tantalum ones. Never had one though that would bring down the entire board. Dave did try running the machine with an electrolytic in the end and there was still damage. I'd expect some form of short protection, a PTC fuse at the very least on whatever else that burned out. All of the lab supplies that I use can deal with output shorts no problem (but they also cost a lot more than this little gadget).
@Trump's Merkin
this is not the reason. our input is 60V, there is not any problem
@Dick Fageroni
you can try , my dear friend
trust me
My guess would be stress from the big output leads cracked the ceramic capacitor and shorted it out. The larger ceramic caps can be pretty fragile.
I just received one of these power supplies today, and sure enough, C34 has been edited out. It’s completely gone on my unit. So hopefully that takes care of that!
we have already updated it , use the better capacitor
Oh, did you put C34 somewhere else? Or did you just remove it and make other changes?
Also, while I am talking to you. I'm still trying to assemble my unit. It's just like the one in this video - I have the DPS5020 power supply, and the grey metal case for everything. I am *nearly* there, but I am wondering if there are any assembly instructions you have, such as for the fan board? The fan board is the last thing I have to do, along with the switch. Do you have any manuals?
Thank you! Can't wait to get this power supply working. I also have your USB meter (the yellow one), and dummy load - loving both! I am going to order more, as well as some USB-C ones. Great quality stuff all round! Thank you!
@@uzaiyaro Hi friend
thank you so much for your message and your support, we already change a better capacitor and put it on the front .
for the installation instruction, B.choice 2 (suitable for with power board part product): www.mediafire.com/folder/rsbgws8grh6zo/communication_metal_houing_with_power_board
3.Installation video: ruclips.net/video/ENZg4yTjhnY/видео.html
Rd Tech thank you so much! I’m nearly done with my build, I just have to wire the input side in. If I could kindly make a small suggestion; the crimp terminals you provide don’t fit the dies for any crimp tool I have.
I’ve actually been having a lot of problems with the supplied crimps, but if you supplied the crimps with the plastic sheathes, like the blue, yellow, and red crimps, that should fit a lot more tools and will make better connections.
May I also suggest using ring/eyelet crimps as well? Instead of the two prong style currently used. I found with the build that these two prong crimps tend to slip out if not held in.
Lastly, I’m finding that soldering the power switch can tend to damage it. If you include two spade crimp terminals in the kit, there wouldn’t need to be any soldering of the power switch.
Finally, just a question: has the issue of tightening down the terminals too much been fixed with the removal of the capacitor? I’d imagine it would be, but I have had to make the connections pretty tight so the crimps attach securely.
Thanks glen! It’s been fun putting this together, but the crimps are something I’ve had problems with. Everything else is going fairly smoothly though! Very nice kit. Please don’t take anything I’ve said as criticism, I’m just making a couple of friendly suggestions. Cheers!
@@uzaiyaro thank you very much for your suggestion.
and for your question about tighten, I don't suggest you let our PCB deformation
you know when this is really spooky is when you wake up in the middle of the knight to a beeping detector and search 3 hours for the smell and only find it when you go to your computer at noon 12:00
Mine was blown as well. I just had to check my DPS5020 and that was also smoked underneath. The capacitor was vanished. A few months back, I smelled something burnt but could not locate it. Now I know...
So I cleaned it and soldered in a 100nF 100V PP capacitor as replacment.
thank you for your message
I am so sorry for that, and I am glad that you fix it
if you have meet any problem, please contact me