Today, before the holiday festivities, my boyfriend was using his computer and used Windows to shut it down before he left. But when we returned, nothing starts. No system fans come on. No LEDs. There's no sign of power.
I'm not sure how a cable would become unattached to the motherboard/PSU internally since nobody touched the computer after we left.
I'm assuming it is the PSU since the system shows no signs of life at all, but someone may have a unique experience or there may be something else I am missing.
I built my boyfriend's computer 3 years ago, here are the components:
Mobo: ASUS P5Q PRO
CPU: Intel Core 2 Duo E8500
GPU: Sapphire ATI Radeon HD4850
PSU: OCZ ModXStream Pro 700W
Seagate 500GB HDD
Seagate 300GB HDD
RAM: 2x 2GB Corsair XMS2
Shut down with Windows, now computer won't start at all (no fans, lights, etc.), suspect borked PSU. Thoughts?
PSUs do tend to reach the end of their life pretty often in the 3 - 5 year range so that is a strike against the PSU.
Do you have a PSU in your computer you could put into his one?
It certainly sounds like a PSU issue.
ModXtreme PSUs were formerly built by Topower so if you have one of the ones from that OEM then that would be another strike against the PSU.
I would definitely try to switch that out first before doing much of anything else if it were me.
You could try the PSU in my signature XFX Pro 650w Core if you are getting a new one. It is made by Seasonic which is the best OEM and it usually has a very good MIR attached which makes the cost very reasonable.
Start by checking power to wall socket. The check power to PSU. Then bypass PC on/off switch using technique in reference above. Last step before buying new PSU is bread-boarding old PSU with a MB you have lying around to rule out a short in your current PC stopping PSU.