Repairing cheap power supplies!

[@DoRC]

no telling if the 20a power supply is fixed without at least putting a modest load on it for a while.

[@JasperJanssen]

Mostly, no telling whether it won’t overheat again. None of the stuff in a PSU this simple is particularly likely to only half-work, though.

[@drkastenbrot]

the failure was likely due to a component faulty from the factory (happens due to wrong handling/transportation or poor qc), so the rest of the psu should be absolutely fine. The 10A psu however had that switching bridge short out so it likely damaged the input circuitry.

[@freeelectron8261]

Sometimes you get electrolytic capacitors drying out due to high temp. Also the PWM IC can get damaged when the power mosfets go short circuit. Love your 3d printer channel - I have learned a lot. Thanks Tom!

[@ZilogBob]

You only replaced the switching MOSFETs without checking anything else to find WHY they failed? Amazing.

[@WorksopGimp]

Cheap low quality

[@xcruell]

exactly my thought. Its like smelling gas in your basement and just opening a window.

[@Passco666]

Yeah that's true, however mosfet is common fail part, which is destroy.over.time mainly in cheap not proper designed power supply if you want to find problem you actually upgrading 20usd power supply. ;)

[@chendotq]

Exactly

[@Seemsayin]

@@xcruell Actually, no. It's not like that. The smell of gas tells you that there could be a leak somewhere. Ignoring it could be lethal. Not the same as not fixing a $25 PSU.

[@sdubvt]

You gave up to easily on the 10A supply!

[@SianaGearz]

Yes i'm so dissapoint, Tom son! It's likely just a dead feedback resistor or the Zener diode. Just check everything in circuit and see whether something shorts that shouldn't, or something is open that shouldn't be, and i think with 80% probability, you would have seen what the issue was. Other 20% say that you'd have to lift one leg off every component till you find the fault :(

[@richardgoebel226]

Yes, all he did was replace the obvious, damaged components. Troubleshoot the 10A!!

[@eldontyrellcorp]

Agree... Unfinished job ! The most interesting part is investigating even if it takes time. I repaired a power supply for a friend inside a RGB laser. It was the shottky diodes.

[@boblewis5558]

Agreed. Surprised that you didn't mention or check the Schottky diode/s as they are quite often under specified. The current rating may be fine on paper, but when frequency and temperature are factored into the equation they can quite often fail even if the rating appears adequate. It's also a VERY quick and easy multimeter test in circuit to find out and checking the forward voltage drop when the supply is on will confirm also.

[@DominicClifton]

Yeah, find the fault!

[@3DPrintingNerd]

I really liked this video, Tom. Not just the content (killer, as always) but the style, the pacing, the scene editing choices. It felt very "I Like To Make Stuff" and it felt like you were really able to convey more to your audience.

[@MadeWithLayers]

+3D Printing Nerd thanks! I like the ILTMS style a lot and am always experimenting with new workflow, this one felt a lot more dynamic than what I usually do! Usually, it's doing th thing first, then scripting, shooting, editing - and usually another round of shooting after that.

[@phanom3658]

True his videos are very professional. Yours are awesome aswell. Just made your fidget spinner!!!

[@lilypower]

3D Printing Nerd yeah, good video, and I have to ask if you made yourself a couple of Adam savage mic eyeglasses? :) I'm sure he's not the only one in the world that has made a pair but he's the only one that has made a video as far as I have seen :)

[@unlost117]

My boss says"wots that". I said "fidget spinner". he says "Gimme a look". I have not seen it since he took it off me !

[@phanom3658]

lol there so addictive

[@BryanChance]

"Uh-oh the car doesn't start, tried turned the key twice. Well, the car is broken.. throw it away.."!! ;p

[@trabadix]

Exactly, this man seems more like a parts changer than a true connoisseur of electronics

[@S3rial85]

Just send the defective one to BigClive, he loves that stuff ;)

[@giusn]

Sebastian surely he would fully repair and possibly upgrade it, but then he would blow it up with or without dynamite, just to make things more exciting.

[@JamesMossR33]

I'd love to see BigClive fix it.

[@stewartcaldwell5299]

@@JamesMossR33 It's gotta go BANG !!

[@tjones99]

Best idea ever... if you post a video asking for help, probably get very few suggestions... post a video where you FAIL and everyone is in a hurry to jump on your failure and show you how good they are by telling you what you did wrong... now you have a bucket full of suggestions to try! Love it!

[@pinkponyofprey1965]

Yes! That's a concept for a career on KZbin haha! :D

[@hamadyt956]

the rule of repairing is to repair the thing which cause it to fail not faild component

[@SchwachsinnProduzent]

yeah, but at least there is a chance that both parts are the same. If you aren't good with trouble shooting, you can always just replace things like destroyed caps or parts that have cooling that might have gotten too hot, because of continous load. At least there you can guess that the broken part wasn't killed by some other broken part.

[@American_Aliens]

I was convinced he knew what he was doing until he failed with the 10A model.

[@masterofnothing2125]

me too

[@xConundrumx]

aww, I feared that would happen.

[@adrianangka]

Its easy he must check the 2,2 Ohm resistor at the base transistor

[@zippyzonka]

D7 slot was fitted with a resistor. Maybe something to check...

[@EscapeMCP]

Re: oversizing power supplies. I'd go much higher than a 15A supply for your 10A load. I'd opt for 20A or more likely *30A*. These PSUs will be overspecced anyway, so a 30A supply will be just about ok with 20A, but get it to power 10A and it'll run for much longer (and much cooler). Don't believe those eBay specs because Chinese watts are quite a bit less than Western watts. *ALWAYS* use the conversion rate: 1CW=½WW and you'll have far more success buying cheap Chinese electronical goodness.

[@ProtonOne11]

Thats a good idea. And most people seem to think that the PSU can deliver it's rated power at all times. If you put it in a closed box, like Toms lamp, it will heat up the inside of the box to a pretty high temperature (warning: possible fire hazard!). So make shure to keep in mind that rated power is usually just good for something up to around 40-50°C and in higher temperatures you have to quickly reduce the max power you can pull out of that supply. Usually that information is written in the datasheets or in application notes (good luck finding reliable data from no-name chinese manufacturers...).

[@1pcfred]

I was just watching another channel where a guy wound a 10A rated SMPS up to 14A and it was still not sagging voltage. But how long the unit could do that is debatable.

[@SnoVVdogsPks]

Or buy genuine western PSU's, I mean, even genuine Meanwells and such aren't so expensive.

[@alejandrodelabarra2838]

😄1 W Chinese=1/2 W American

[@ArnaudMEURET]

@@SnoVVdogsPks Exactly ! Buying reputable chinese brands is like buying reputable _anything_ brand ! Playing along with the bad actors is a recipe for sustaining bad behaviour. Stop this "chinese Watts" BS @EscapeMCP!!!

[@paziipa]

Also a good thing to check and fix with these chiinese models is the grounding, I've had multiple ones with ground not connected to the casing..

[@stephenbeeson1521]

I would recommend caution with the heatsink pads, they most likely provide isolation between those fets and the heatsink which is tied to ground. Most fets do not have isolated tabs.

[@falconthree3815]

Just starting in repairing board(77 years old) great video,thank you. 😎😎😎

[@mohamedkikia7338]

I just came across his video now. Usually when the 2 switching transistors pop the 2 resistors on the base of the transistors also pop. These are normally 2.2 ohm. This is a quick fix. I also test the power supply before putting it back in the case. Another good practice is to use a 60W or 100W light bulb in series with the mains supply when switching on. This limits the current in the event of a fault still being present. If the light bulb glows brightly you know that there still is a problem. I also do a load test once the repair is complete. Quite often the power supply works under no load conditions, but switches off under load. Anyway keep up the good work!

[@AlanLiefting]

Given the failure modes I would have thought that they failed due to a power surge but the NTC looked like it may have been poor quality given that the bond for the lead had failed. A few more points: 1. The mains capacitors do not always remain charged. It depends on circuit design, bleed resistor failure, and when it was last powered up. 2. A lamp is a handy discharging method. 3. It is very easy to check for charged capacitors with a multimeter. 4. Don't use tools to discharge capacitors. -- It blows holes in the tools. -- You should be using good quality tools and that is not the sort of treatment you would give them. -- The sort of currents that are generated may be bad for the capacitor. 5. Never put the covers back on until you have carried out tests. If you feel unsafe without the covers on you should not be be anywhere near the tools. 6. Your soldering of the bridge rectifier was very poor. Solder joints should have nice fillets and should not be blobs. Obviously the legs were not tinning very well. What you should have done was to clean the legs back to bare copper and then resoldered it back in place. 7. You should have cleaned the thermal paste off the sil pads, especially if it was dry. 8. Whenever the switching FETs have blown there is a huge procedure to go through before applying full mains power. Too long to outline here. 9. The Faston crimp connectors were not needed in this case. All you were doing was a bench test and the terminals on the power supply had a square securing washer designed to clamp directly onto the wire. You wasted three crimps. 10. Invest in a hand operated desoldering pump (at the very least). The method you used for desoldering is tedious and puts unneeded thermal stress on the pcb pads.

[@darkshadowsx5949]

soldering pumps are way better than wick. he didn't need to cut the legs if he had one... soldering pumps can last a lifetime. while wick is consumable. The crimped connectors are perfectly fine.... it makes it look neat. sure not necessary but it also helps avoid the chance of a unseen loose wire strand making contact with neighboring terminals. No need to criticize his use of them. highly unprofessional.

[@iuries]

Just an advice: it's always better to discharge the high voltage capacitors with a 100-470 kohm resistor. This way you're saving the capacitor from excedingly high currents through it.

[@ZilogBob]

100-470 *ohms* does not take all day to achieve that.

[@tonigood7245]

There's a technique to soldering..... This gentleman makes it appear easy.

[@ejohnfel]

I would agree with some of the comments here, a little more detail on how to safely discharge the caps is in order. Other then that, well done.

[@1pcfred]

Safely for what? You or the capacitor? If you really want to do it safely then you should use a bleeder resistor. Because just shorting a charged cap out you can blow holes in the dielectric.

[@jeffbeck6501]

Nice electronics skills like cutting off the power transistor so you can unsolder one leg at a time, and also mounting the pcb on a vice vertically. Nice work.

[@hullinstruments]

Would love to see you do more circuitboard troubleshooting videos. I like the way you explain things, and even though you might not be an electronics tech professionally…… It’s always fun for the audience to watch and learn along with you. It’s especially satisfying for guys like me who are professionals and do this full-time, to watch smart and competent folks like yourself learn and grow in their understanding of electronics. PS… Check the zeners and diode‘s on the supply you couldn’t fix. Probably the issue it is very common. Always think UPSTREAM of a failed component as to WHY it failed. Don’t replace a fuse or transistor without figuring out what made it fail. Also a somewhat lengthy load test would guarantee their function for the future. I really enjoyed the video!

[@JohnUllrey]

Very cool LED light fixture. Have you thought about making a quick video about how you made it?

[@masterofnothing2125]

when I hear the sound bite is clear, your voice is understandable and your workshop is amazing, I immediately click subscribe and thumbs up, when you try to discharge the cap that way and failed on repairing the 10 Amp, I immediately regret it.

[@mrechbreger]

Very healthy and safe discharging (although not for the component itself).. I think this should have more attention

[@Red_Avenger]

After replacing the switching transistors, on the hot side, it is necessary to check the circuits from the transistor base (resistors, diode and capacitance). To connect the power supply for inspection, it is necessary to use an incandescent lamp of ~ 100 watts instead of a fuse. This will protect the power supply from damage in the event of additional malfunctions. And you can use this lamp for discharging power capacitors.

[@matthewq2365]

Man I so need to do this work on my broken power supplies. The printer's been down for 6 months and I miss printing. Good work Thomas

[@pharmadonaniketgarud2598]

One must appreciate the style and knowledge given by this guy, Really loved your VDO it is helpful plz make vdo on how to check how much ampere is giving by power supply.

[@dakotapahel-short3192]

Definitely would love to see more videos like this! My 3d printer build experience allowed me to fix my 500 dollar computer monitor by taking it apart and re-soldering the power connections. I've gotten 3 more years outa that monitor thanks to knowledge like this.

[@BrilliantDesignOnline]

Like your style and speed of delivery: no nonsense. And that you comment to discharge the caps. Would have liked more on the 10A or put a follow-up link to vid in the comments of this one. I am not a beginner, but a refresh of your logic and steps is great. Thanks. Also: Do you have a link to the ceiling lamp (very cool!)?

[@imqqmi]

great video! Use a little flux will improve both soldering and desoldering and allows you to use lower temperatures. You can also preheat the pcb by putting it on a heated bed at 110 degrees for 10 mins.

[@juschu85]

Yes, you have to discharge those capacitors before you touch anything on the PCB. I had to learn that the hard way when I repaired an icecream machine. Let's say I was really wide awake after I touched the PCB on the wrong trace. But at least now I can make my own icecream. That's worth it.

[@devrim-oguz]

Check out the toroid coil connections on the 10 Amp power supply. They got broken easily and it could be the problem. I got the same led not working and no power output issues and I finally found out that the toroid's connections were broken.

[@devrim-oguz]

It has some connections hidden in the middle of the toroid.

[@moeezamjad5949]

In this case, when transistors or mosfets are burnt, the resistor connected to the gate of both mosfets also burn out. That are usually of value 1 ohm. Same case was happen with me on 12v 30amp PSU.

[@Aaron-jk9zj]

A lot of these cheap power supplies don't have continuity between the earth terminal and the metal casing. I've bought a few of them, only one had continuity. Always check and if yours doesn't, just link one up to the side via one of the mounting screw holes.

[@electronic7979]

Helpful repair video 👍

[@meta-memes9060]

Love the speed, focus, and clarity. Great vid!

[@HoaPham-zs1mh]

Wow that's such a cool ceiling lamp!

[@ljprep6250]

Thanks for finally deoxidizing and retinning the soldering iron tip at 4:40 or so. LOL Good, fun repair video, thanks again.

[@electronicshelpcare]

Great video as always. Keep the good work, sir.You are the best teacher.I have learned a lot from you 😁

[@kaitofujiwara9742]

Keep up the repair contents. It's quite educational

[@azertaieb442]

Thanks for that good job ...i wan ask you if this power supply can it charging a lithium ion batterys ?? Thanks again

[@peterzeboroff7448]

I would like to see many more of these power supply repair videos but in real time please.

[@1959Berre]

Ever tried a spring pump to suck out the solder tin? Works like a charm.

[@samdeur]

Like this vid. Only thing that was missing for me as a noob was the settings on the multimeter.

[@lucasskorvodovski683]

very good video. Could you tell me the values of the transistors of the second source that you repaired because I have the same source but a transistor exploded. Thank you so much

[@wilsonjudy9515]

video quality is really good

[@72Z15SS]

I just lost a power supply at around 90% of a print being complete and I took it apart to have a look. I think it's repairable but not sure if it's NTC's or capacitors on the input side. They're light blue like the ones in your 20amp model.

[@1pcfred]

Do an image search for 472m Y1 capacitor and see if that's what you're looking at.

[@72Z15SS]

That is what they look like. I just received an e-mail form the manufacturer, they are sending a replacement and want pictures of the blown unit to see if there's anything burnt I guess? This will give me the opportunity to pull them out and try replacing them. I have a local Radio Shack close by that has not yet closed and they just might have some of these. Thank You Sir for your advice.

[@1pcfred]

+72Z15SS I doubt Rat Shack will stock those. But you can salvage them from many SMPS PSU. That's where I got all the ones I have from. Old PC PSUs are a great place to get them.

[@72Z15SS]

I just opened up an old pc power supply to take a look. I'll dig a bit deeper when I find some more time. The Radio Shack I went had nothing.

[@1pcfred]

+72Z15SS The Y caps should be by where the power goes in. Sometimes they are a glossy tan color too. They're always about the same shape though. Because they are the same thing. I guess it just depends what kind of goop they have at the factory when they're making them? Maybe the tan ones are a different value? I honestly don't know. The value is printed on the sides of the parts. But it is hard to read. I use a magnifying glass. Plus a meter. A meter won't tell me what voltage the part can handle. At least my meter doesn't.

[@werner1]

The first time i had to wire one of those units i had to wait an extra day to overcome my nerves, i had a nice wiring diagram but i never trust anything a 100% luckily the diagram was spot on. Thank you for making this video i'll re-watch it if needed. Have a nice day

[@francoisguyot9770]

You should check the feedback circuit, usually a TL431, the opto coupler and perhaps the TL493 PWM that drives the MOSFET.

[@chbonnici]

Thank you for the nice video. Please could you tell us what IC driver they use For the switching frequency. BTW do you know the switching frequency ? Bless you.

[@roboticsgenius]

Awesome video, as always! As a follow up video maybe you can do some upgrades to the power supply? Not many of us would know how to upgrade the power supply to better components(if it's worth it)!

[@MadeWithLayers]

+roboticsgenius totally not worth it - Meanwell suppliers aren't that much more expensive and deliver exactly what they promise, if you try to improve these cheap ones you'll just run into one bottleneck after the other.

[@nickmoxley6038]

Where did you get the little ball vice from ?

[@lostname605]

Nick Moxley I own the same model as Thomas. It is called a Precision Vice FMZ by Proxxon. I think it is really good!

[@zaplocked]

PanaVise 301 is a good option for US folk

[@WreckDiver99]

in the US, any Harbor Freight has these...I have one and love it. Cheap and it works. The Panavise 381 is pretty much the same, but it's about 3 to 4 times the cost.

[@zaplocked]

the closest thing hf has is the 2-3/4 in. Articulated Vacuum Vise, which looks ok enough for the price, though I prefer a clamp or just really heavy base over a vacuum. I do like all the accessories you can get for the 301 though

[@WreckDiver99]

yea...I modified mine and it's bolted to a board that I can clamp anywhere...

[@armunro]

One mine it was the 105J 400v capacitor (1mF). Need a capacitor testor for that (I use an LCR component tester). I know its 3 years on; did you ever fix the 2nd one?

[@AJB2K3]

Have you heard of a solder sucker/pump? I find they are better then wick

[@JamieBainbridge]

I have a $300 solder station with a solder sucker gun, but people like Tom and 8-Bit Guy can desolder better with braided wick than I can with my fancy expensive thing.

[@1pcfred]

Good braid can actually be more gentle on board traces. You can suck solder rings right off PCBs with solder suckers if you're not careful.

[@SianaGearz]

This is a single sided board! This is why it cleaned out so easily with the wick. When you have through-plated holes, wick tends to fail, but a bit of flux and it might be good. I personally find solder suckers to be more aptly described as board whackers, but i use them too :( might need to get a better tool.

[@1pcfred]

+Siana Gearz board whacking works. My boss at the board house I used to work at taught me that technique. Just slam the board on the edge of the table while the solder joint is hot, and the solder all flies out of the hole. We called it heat it, and beat it.

[@SianaGearz]

But they aren't even good at board whacking. Besides, i think whacking a board with unleaded solder is not the brightest of ideas if you want it to be reliable afterwards. I mean sure, it's likely to be fine, i'm just not comfortable with the idea of whacking brittle joints.

[@christicarl4612]

Thank you now I wont have to buy a new lap top my plug is loose and so mic plug. im going to try this. Is it the same on computers, lap tops?

[@PupettaZoccola]

Thanks for sharing this video, if condenser and inductor white liquid comes out, the power supply can be repaired

[@grantemsley1]

I wish you mentioned HOW to safely discharge the capacitors. Not everyone knows how to do that safely. Otherwise good stuff!

[@jonstenSE]

But he do, at 4:00

[@grantemsley1]

He does it, but doesn't actually say how he is doing it. you just see him wiggle a screwdriver. I mean, I know what he did, and you know what he did, but not everyone will, and I just don't want to see anyone get a nasty shock.

[@jonstenSE]

That's true, had the same reaction as you initially in the clip, he could have stated it clearer.

[@feedtheagle6851]

He used an insulated tool to connect the two sides... that said, it is a huge liability to tell people how to do it. If you are at all uncomfortable or not 100% sure that you have discharged the caps... don't continue.

[@grantemsley1]

Oh that I agree with. So just say that - if you don't know how to discharge the caps, just stop now. Or go learn from someone else and sue them if it goes wrong. I just feel like it was a little bit too glossed over for such an important safety step. Then again, this didn't include a step by step tutorial on how to (de)solder things, so I guess some basic knowledge is assumed in the viewer.

[@victoryfirst2878]

Thank you for showing me something new and how to repair stuff too. Good day fella.

[@ryangarrison7088]

You are by far my favorite 3D printing KZbinr to watch. Thanks Tom.

[@Darieee]

Make sure to also check SWISTONE soldering wick, works way way way better than the one you showed

[@waderedsox]

thats a really cool lamp

[@tcirit]

I bought cheap one from Amazon (36v 10A). Is it possible to upgrade or make more reliable it replacing its chunky components with good quality ones? Thanks for your video.

[@lancelnce]

I just fixed one of my power supplies these days, the chip providing power_ok was bad even if everything else was alright, so i just put a inductor on the 5v signal and make a power_ok signal myself and voila! Fixed! I wanted to replace the broken chip but heres nowhere one of these on all my power supplies scraps here.

[@charliebowen4232]

What kind of vise is that? Great video...

[@vladtomoiaga4721]

It's a Proxxon Precision Vice FMZ (a well-known German brand)

[@charliebowen4232]

Thank you Vlad!

[@MadeWithLayers]

It's the Proxxon 28602 -> geni.us/vise

[@waroo0007]

Nice video.... ive a little question (before ask, i have not much knowledge on electronic... ), ive a power supply that just shut off while it was charging and of course when you plug it in doesnt start at all... my question is what should be checking/looking for with the multimeter to try to find a way to fix it... hope can help thanks once again good video

[@thebrakshow7415]

Its mostly that output rectifier diode that is bad. I cant tell what refdes it is but It is what HS1 (heatsink) is holding.

[@Labyrnthdom]

The 10amp most likely needs a cap or two replaced. Easy fix. About the high voltage caps holding a charge. It is very possible it can hold one. Especially if the discharge circuit has been damaged.

[@rossfisher323]

Meanwell Power Supplies tend not to burn your house down.

[@koohoo4500]

Mean Well doesn't then teach how to put out a burning house, so no points, mate.

[@MadeWithLayers]

+Ross Fisher yup.

[@clifffton]

Mean Well won't give you a reason to watch a dead PSU video ;)

[@TheSlimShady87]

When it doesnt start ,check emitter resistors ! Mine blew up once with transistors

[@primusjohn8585]

Nice work sir

[@JamesMossR33]

With the 20A PSU fixed would it not go again? What might have caused it to blow in the first place, maybe too high a load on it? Just curious.

[@MadeWithLayers]

+MrChops constant high temperature - it was housed in the center section of the lamp where there's little ventilation, I guess the components just degraded after many hours of use. The 20A model is fine and perfectly functional, but the 10A one is not.

[@radius.indrawan]

4:40 the transistor's leg closest to camera seems protrude a little, way too close to the edge of the board and might touch the case when assembled.

[@JJ-nj3pd]

First video I see, then went straight to your channel.. very useful stuff mane, of course I subscribed. Keep it up 💪

[@ThingEngineer]

Great video! And love that lamp and paint job, super clean and techy.

[@Inquire98]

REALLY good video 👍

[@Enjoymentboy]

I've got a 15A version of these and from day one it has had issues. Only outputs 10.3V at around 500ma. The adjustment pot does nothing. No parts have any obvious damage. All solder looks good (shockingly). No bridging or breaks. No corrosion or burn marks. I've tested every capacitor, diode, resistor, ntc and transistor...all test out fine. I'm completely stumped as to what the issue could be and see nothing about one of these outputting a voltage lower than should be. I've already spent more than an hour on this thing and for the cost and what I make I could have bought 2 more of them. lol And of course the seller has disappeared so no chance of a refund. Any ideas what else I can check?

[@Savagetechie]

knipex, proxxon and wera. You sir have great taste in tools. Although my love of knipex is not good for my bank balance.

[@dntlss]

I had a question, i dont know the first thing about this stuff but i always love to watch people that know about these things and how they fix them etc, pretty cool, i have a buddy that has a toolbox that came with a stereo in it, here recently it quit working, the stereo is a 12 volt job that uses one of these power supplies and i have isolated the problem to the power supply etc,looks just like this stuff your working on,i am going to buy him another one and get the radio going. My question is, how long can one expect for one of these things to last? he doesn't mind paying 50 dollars for one of these but from what Ive seen these can be had for hardly nothing, obviously because they are made with cheap stuff, is there a workaround this? or just buy another one and it might last a year or so? he uses this radio very little and to be honest he bought this toolbox like 10 years ago and that power supply just now quit working so i guess he got his moneys worth out of the thing,lol The less you use it the longer it will last? is that what it boils down to? thank you so much for your time and input.

[@trabadix]

This man seems more like a parts changer than a true connoisseur of electronics.

[@JMMC1005]

What was the original solder on the board? Leaded or non-leaded? (It's hard to tell whether the dull joints are unleaded solder, or just dry joints). If it's leaded, you'll probably have better success using a leaded solder; I hear the two types really don't work too well if they get mixed.

[@DoctorEd]

Did you check the other side of the transformer for a shorted winding?

[@Dualecosse]

Thomas, I'm impressed much better than when you sometimes do wiring live !!!

[@bayareapianist]

Those transistors are called FETs. were there FET both the same? any spec needed to know except the breakdown voltage? do I need to like if they are n-channels or p-channels?

[@timmeke_8213]

did you use lead free solder?

[@chandannn]

Getting 6V instead of 24V, tried adjusting voltage but doesn't see any change. Perhaps, potentiometer has gone wrong? Any input will be helpful Thomas. Thanks for the great video.

[@Nullzero98]

Hey Thomas! How about a review of the Prusa multi-material upgrade! I can't find any good ones on KZbin at all!

[@MadeWithLayers]

+Nullzero98 is it even fully released yet?

[@floriworidikkedori]

No it isn't, but they will start shipping soon according to the prusa blog. www.prusaprinters.org/update-multi-material-upgrade-2/

[@Nullzero98]

Oh, good question. I guess the pre-orders start shipping this month. With new orders shipping in... AUGUST! Wow, quite a backlog. shop.prusa3d.com/en/printer-upgrades/118-original-prusa-i3-mk2-multi-material-upgrade.html

[@thevoidedwarranty]

check the low value resistor below the mosfets u just changed , they are usually 33 ohms

[@anirudhkundu3567]

Do these power supply have any kind of voltage monitoring or over output voltage protection?

[@p8051a]

How do you like the Proxxon vise ? Is the ball assembly flimsy (like I've read on some reviews) or sturdy enough for light duty stuff?! Thanks:)

[@MadeWithLayers]

+Takis it's all cast metal. The clamping part slightly deforms the first time you tighten it down really well, but after that it's rock solid. Of course, it's still a ball head and there's no no way to clamp that tight enough to stay put when using the vise as a forging anvil, but it clamps down well enough for soldering, tightening screws or even for using a file on metal parts.

[@p8051a]

If it really stays put when filing metal it's good enough for what I need ( small yet sturdy vice for electronics). I have a large vice for heavier jobs; just needed something light for finer tasks. Thanks for your quick reply.!

[@unionics]

Hi Thomas my Metal 12v 4 Amp power supply has static current on 12volt output and its showing from tester. So should you please do let me know which parts need to be replaced ? All diodes are OK. Few days back the static currents are not there ..

[@VorpalForceField]

not advisable to repair power supplies unless you can actually trouble shoot electronics ..

[@jerrywi6172]

Hello sir, I try to fix power supply that lacking the amperage, the voltage output is fine. Can you suggest what component should I replace it? thx

[@charlesbaunsgard4000]

What crimpers did you use for the spade connectors? I have been having problems locating a good model.

[@bbogdanmircea]

Charles Baunsgard me too please send Amazon.de link if you find out

[@shanestraub2111]

What about the thing with the copper windings that looks like a ark reactor thats near the small capacitors mine looks fried

[@oskarogarp]

Don't forget that there's often a potentiometer that can adjust the voltage if it's to high or low.

[@ProtonOne11]

Just FIY, that potentiometer is there to compensate for the losses in wiring. If your load is a few meters away from the power supply output, you increase the voltage on that pot to give the load the nominal voltage it asks for under full load.

[@zaprodk]

The power supply you couldn't repair, i'll bet a zener diode is dead. Do a diode test on all diodes and you will probably find one dead.

[@MadeWithLayers]

Thanks, I'll test those!

[@KugelXFanger]

@escorpiuser could be the caps, but normally you should see them bulge up if they are broken.

[@kayquexavier]

well, the controller IC is a major problem too, if the IC is fried it will burn your mosfets and diodes endlessly

[@wadib3eed7]

most of these types of power supply used PWM IC and in that case no output voltage maybe PWM IC has the problem

[@iyathsuzuki]

0000adeq=p

[@xcruell]

Please only teach things you really know. This is too dangerous. You replaced the blown mosfets, without caring about WHY they blew. Thats basically the best example

[@spikekent]

What is that vice called? I've been searching for a while and still not found it, probably cos I'm not searching with the right terms. Keep up the awesome videos, I learn something new from every one.

[@lostname605]

Spike Kent I own the same model as Thomas. It is called a Precision Vice FMZ by Proxxon. I think it is really good!

[@spikekent]

@LostName Thank you, I really appreciate that. Now I can finally get the right one.

[@bentlikeitsmaker]

love the light fixture would love to know how you made that looks amazing also personally like the meanwell ipx rated i know there expensive but hey they last so you use alli express ever used digikey or mouser theres one other as well allied electronics they carry stuff all the way up to vac motors

[@davidteale4270]

Had a cheap Chinese SMPS 12vdc 15 amp go down on me the other day. It's been working for the past three years 24/7, So I looked into repairing it, I found the caps had dried out so I went online E-bay to buy some new ones, 200vdc 220pf ? Lowest price for a pair was approx £6? I looked on line to see how much a new SMPS was of the same build 12vdc but 20 amp instead of 15 amp price£7.20p, so I'm using the old supply for spares and buying a new one, the switching transistors look a bit worn as well so add the price of trans/caps? it's far cheaper to bin and buy new one!