|So, since I didn't have too much pressing stuff to do[^], I decided to fix the desktop PC that gave up the ghost a few weeks ago. I was working along, all of a sudden a snap sound, the machine went dark and wouldn't turn back on. Since I had pressing work to do, I simply moved over to my backup PC and kept working - didn't lose hardly anything thanks to OneDrive and frequent backups. I figured the power supply went - they tend to do that every 5 years or so.
So, today I opened the machine up, pulled the power connector off the motherboard, short pins 15 &16, no power. Yep, power supply is gone. Run to the local repair parts place, plunk down $40 and come home with a new power supply, plug it in, short pins 15 & 16, seems to work OK.
Remove screws and connectors, pull old power supply out of case, put in new one, connect cables. So far I've spent about 30 minutes, not counting the errand I ran while picking up the new supply.
Power on. Nothing.
Check all connections, OK. Pull plug from motherboard, short pins 15 & 16, power comes on, disks spin, etc. Supply seems to be OK. Plug cables back in, nothing. Take lunch break. Back again, check all connections, recheck old supply, take case off other PC and compare. Nothing seems to be wrong, except it doesn't power on. Finally pull the whole box ready to put it in the car to go to the repair place in frustration. Decide to call them to see if they have time to trouble shoot if I bring it in today.
Sure, they say, but first did you check that the power cord is plugged in. Yes, I'm not an idiot - the fan turns and there's power when pins 15 & 16 are shorted, so it has to be plugged in properly.
Did I turn it on? Yes, I used the switch on the back of the power supply. That's how I got the fan to turn on and the disk to spin up. Do you think I'm an idiot?
Did you press the power button on the top of the case as well?
Well, I only lost about two hours finding out that I am after all, an idiot.
BTW, the power supply works fine and the machine is back in use again.
CQ de W5ALT
Walt Fair, Jr., P. E.
Specializing in Technical Engineering Software