Chosen Solution

Hi All, After the sucess of fixing a reluctant display, I’m now presented with a PC power supply that’s decided to throw in the towel. Said PSU is about 5years old, and thanks to MS patch tuesday forcing a reboot of the computer, it then failed to start, the case power LED blinks once, whilst the internal fans spin for about half a second, then a faint click, and it goes dead. A short while (20/30 sec) later, it tries again, with the same results. Sounds like the PSU is attempting to fire up, but isn’t getting there somehow. Pulled it out, popped the lid on the PSU hoping to find some easy to replace capacitors bulging a bit, only to find everyhing looks as it shoud (bar the dust):

Any thoughts as to any avenues I can follow regarding testing before I can it and buy a replacement? Cheers

If you’re not even reach a Windows splash/error screen you’re definitely looking in the right place for a physical issue of some sort.

I’d pickup a PSU tester on amazon (https://www.amazon.com/Computer-PC-Teste…) and test it. If you for have a known-good power supply, I’d connect it and see if that allows boot.

Additionally, flip your PSU power switch off for several seconds and then back on. I’ve heard of this resetting internal breakers in some PSUs, but I’ve never personally confirmed it/seen documentation of such. Haven’t searched/tested specifically for it though.

If it tests healthy, a swap with another PSU produces no change, and the switch flip does nothing - potential motherboard failure would be my next stop for testing, but most of the time I’ve encountered that on the rare occasion I was lucky to still receive error beeps from my board for troubleshooting during attempted startup.

Best of luck.

@gilesp I don’t know the PSU for your PC but if you have a DMM (digital multimeter) use the paperclip test to check which of the various output voltage supplies is not there from the PSU If some are low or even missing then check the capacitors in the failed PSU i.e. bulging or blown and also for any other components that look stressed or heat affected. SMPS power supplies put a lot of stress on the components. Be careful if testing inside the PSU without a schematic as there is exposed lethal AC in there. It is safe on the output harness connections though as that is DC although you don’t want to short that out either