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

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

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!

You gave up to easily on the 10A supply!

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

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

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

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.

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.

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..

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

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

Hello there . I would like to know whats the best input current needed for similar device =24v 20a output= to fully function to 100% ???

Hey Thomas, thanks for sharing this video! I have a power pack on my run of the mill 3d printer that seems to be almost identical to these. One day while my print was paused one of the smaller capacitors exploded so i purchased some replacements and swapped the old one out. Put it sll back together and it blew again! Does this seem like something would be putting too much load on the power supply or perhaps anothe faulty component on the supply? Any advice would be greatly appreciated. Luke

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

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

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.

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.

Hi Tom, I bought a 60A power supply for my 3D printer and now it always blows the fuse. After fiddling around I found that the both AC lines are connected to the fuse, which makes it blow. Is it also a damaged NTC? And is there a certain capacity and/or value for the NTC parts?

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.

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

What maximum load would you recommend to put in a 5V/60A power supply? I'm going to use such two power supplies with a LED strips (SK6812, 60led/m, length approx. 15.6m and 16.2m).

Wow that's such a cool ceiling lamp!

hey if my power supply (with nothing plugged into it except power) has a blinking green light, how do i fix that?

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

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

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

what power supplies would you recommend that are a bit more robust?

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?

What goes when you had the 110volt setting with 220volt input?

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.

Did you ever get the 10 amper? I had one that was bad because of bad solder joints on the switching xfmr. And if it's rated for 10 amps, I wouldn't draw more than 8. That chock over by the switching xstr's looks a bit small.

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.

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

I'd love to see more of your ceiling light. That is so cool.

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.

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

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.

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!

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.

thats a really cool lamp

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

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

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.

when I try to check my power supply with a multimeter in continuity mode, v + and v-paths are connected !. is it really like that?

Helpful repair video 👍

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

bought a 3d printer with a Sompom S-360-12 power supply that wouldn't turn on out of the box. After tinkering around I got it to start for a moment or two then when I turned it off it wouldn't turn back on. after tinkering around with it I believe that the problem with it is the switching transistors and or thermal pads. How would I go about fixing this? is it the same as shown above?

Keep up the repair contents. It's quite educational

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.

My old computer smps works fine for 1-2 hours after that pc begins to restart again and again, but it never goes beyond the initial boot welcome screen. Any ideas which components might be failing? Is it repairable or shall I buy a new one? Thanks

I have this same power supply. It is ok and giving exect output 14v. But when i put some load on it it goes off what happend with it? How can i recover it

Hi i brought a New Dlink 8ch Power Supply, after plug In When am connecting the cctv Power wires into Power Supply with Tester, in that it Shows POWER on -Ve & +ve also So is that Power Supply working Condition good r in Problem. Adv Thx

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

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.

Hello Thomas, What is difference between adaptor and charger

i think a short on my heated bed caused my 20 amp 12v PSU to pop. looked inside and there is no evidence of anything wrong, but it passes no power. any idea what link in the chain is likely to fail due to a short?

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?

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

It's a useful video if you have a visible damage. ...and while I'm here, I have question: one of my similar power supply has 100~ volts in the casing under load, any ideas how that couls be repaired?

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

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!)?

Hi, I have a 12V power supply from a Anet that only outputs 8.5V even with potentiometer at maximum. No broken/smoken components are seen. No open/shorted diodes. Any suggestion?

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.

Thanks for the quick overview!

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)!

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

Hi, Good day question about DC to DC. What is the best to be use a diode or resistor to stepdown 5v (USB) to 3.3v (Webcam module laptop). Thanks

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?

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.

Is the Meanwell MW SP-200-13.5V any good.

My 5 volt 40 p power supply get treap when I on ac supply ....what I do to solve these problems ?

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!

Great channel, love that LED light too

Nice work sir

Don't these PSUs typically have bleeder resistors? I tested a desktop PSU a while ago and it took under a minute for the caps to discharge.

How do you make sure they're empty tho?

Wow I like those glasses. Do you happen to know where I can find that frame?

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

Hi part number transistor switching A-200-5?? Thanks

my psu is outputing 4 VDC instead of 12 VDC, could it be the transformer?

Nice repair 😎

I had a 24v 10a smps similar to yours, i hear some noise and an output open voltage reading of 19v, and won't adjust even after turning the adjust pot, where could be most likely the culprit?

How I do check of burned capacitor. Like small size of MOV

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.

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

My PSU that came with my Prusa i3 MK3s shows 6V on the outputs...

Does @Thomas Sanladerer have a build video for the LED lamp thing that he showed off? it looked very interesting, and i kind of want to build one.

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 ..

How can check the damage transistor before replacing

why a atx psu will not take 6amp load when its allready on

Thank you, learned a lot!

great video as usual !

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

Oh! Great, Thomas. I have one of this broken psu here but never tried to fix then. :)

Great video. I've got a monitor power supply board laying around that has leaked capacitors and a burnt chip that is too heavily damaged to read its name. Unfortunately I cannot find schematics to the board. How could I find the name of the burnt chip?

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.

Anyone have an idea what parts maybe going bad if the voltage is dropping? Not completely dead but the voltage is down to half or less than what we need.

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.

my power supply kept turning off its on for a few seconds and its off again. Any thoughts please?