XYH3606 Power Supply Died

[g3force7]

This power supply that I got from Taobao died after I anodised a piece of titanium (1 cm diameter). I set the voltage to 36V and current to 1 A and it worked for less than a minute before it shuts down by itself. If I turn on the main outlet power electricity will flow into the power supply, but it won't turn on. Even when it is not on heat was being generated and it can become too hot to touch. I dismantled the power supply and couldn't find anything wrong with it (no burnt mark).

Imgur album of the power supply: https://imgur.com/a/PYULTj4

[Stephen_Pejak]

Power supplies are fairly simple devices. There could be many things causing this, but I will try explaining to you how to try and find the fault without using fancy tools. Firstly do another inspection and look for any tiny burn spots or cracked solder joints. If you find those, either the solder joint or the component that is on that joint is defective. If that is all fine, buy some alchohol(idealy 99% isopropyl, but ethanol should work as well). Apply it to the components on the board, turn the power on and try turning the power supply on(in case it has a switch). Once you do that look at the alchohol. Where it evaporates first is probably the fault. In case you can't find out anything like that, fault is more complex and definetly requires a good multimeter and perhaps an osciloscope to diagnose. But I believe you will find the fault with alchohol method. Good luck.

[DavidAlfa]

Which  parts are heating burning hot?

[g3force7]

I think I got lucky (zero electronics engineering knowledge), identified the root cause of the problem (dead MOSFETs) and replaced them (had to buy from the power supply seller because the MOSFETs are from unknown source). The extremely hot components (MOSFETs) got my attention, so I Googled "How to test MOSFET" and found a YouTube video. Measured all 4 MOSFETS and found out that 3 of them are dead (low voltage reading between Drain and Source = dead MOSFET).

(How to test MOSFET using a multimeter)

https://youtu.be/8WfETwW6I9M (Before the repair)

https://youtu.be/AxG9GmsTHOc (After the repair)