Hello, I have a PSU that I have had sitting around, and wanted to turn it into a test bench PSU. I originally stopped using it because it wouldn't power up my PC, but would work outside the case. Since pulling it out of the closet, I've been messing with it trying to get it to function again. The PSU is a Coolmax model CUL-850B. Not the best, I know, but not going to be using it in a PC anyway. I opened the case and checked all the caps and circuits to make sure nothing was burnt or bulging, and we're good there. I checked all the screws securing the PCB to the case, and made sure there wasn't anything shorting on any of the wires or on the PCB itself. The power switch went bad, so I bypassed it completely and use a power strip with a switch on it to power it on. When flipping said switch, the fan lights up and twitches a little, then the whole unit shuts down. I put a load on it with an HDD and a few fans, and they don't even budge, but the light on the fan stays on a few seconds longer and I get a bit of a hum sound coming from the PSU. For the life of me I can't figure it out, and the most I could find elsewhere online was nothing but suggestions to buy a new one. As a bit of an electronics hobbyist, that answer does not sit well with me. Any suggestions?