I started with a computer which wouldn't turn on, and now I have a pile of parts. Normal Saturday night, sadly.
Step 1 - Unplug and remove PSU (which requires DVD removal as well).
Step 2 - Short pins 15 and 16 on PSU side to simulate power-on request. Result -PSU fan starts
Step 3 - Plug ATX connector into mobo, press power button. Result - crickets
Step 4 - Unplug micro adapter from mobo, short pins 15 and 16 in that. Result - PSU fan starts
Step 5 - Internet research. Result - confusion
So, seeing as how this is my step 6, what to do next? It appears that the power supply is fine. I tested the connection from the power switch to mobo. I also tested resistance in the mobo side of the atx connector, pins 15 and 16. Strangely (to me) it read that there was some resistance, but not much. Pressing the power supply changed nothing.
Is this a motherboard fail, or is there a clever fix out there?
The power button on the case closes circuit when pressed, but the power supply doesn't turn on. The only things currently attached to or in the mobo are the CPU, the ATX connector (power connector) and the 4 wires which go to the power switch and power indicator light. There is no indication of anything when I press the power button. PS fan won't spin, lights don't turn on, nothing.
rolli, this is a Vista machine, a Pavilion slimline deal. Not too old, I would think.
Two part problem solved with brute force. Replaced motherboard with refurbished model, used original power supply and came up empty. Replaced power supply with new one, which I had tested good with a PS tester, and the machine worked like a charm. So charmed, in fact, that Windows didn't notice the new mobo. Problem solved.