Computer wont power up until I unplug/plug back in the mobo power connector

[Bob Ghengis Khan]

I am running a Q6600 processor on an Abit Ip-35e motherboard with a Thermaltake power supply (not sitting at my computer atm, but I think its a 650w PSU), and 4 gb of Corsair DDR2 Ram

I built this computer a couple months after the Q6600 came out, so its about 2.5 years old (maybe 3?). Until now, I have not had any problems. My computer has just recently started to refuse to boot up after being shut down or put in sleep mode.

There are 2 LEDs on my motherboard, one is red that means the computer is plugged in, and a green one that means it is turned on. After shutting down (or being put in sleep), the Red LED now shuts off, and the computer will not boot unless I unplug the Power cable from the back of the PSU, wait 20 seconds or so, unplug the connection from the PSU to the motherboard, replug it, and plug the PSU back into the wall. Sometimes I have to do this 2 or 3 times in order to get the Red LED to light up and let me start my computer.

What is causing this problem?

Edit: I started experiencing this about 2 weeks ago. I just moved into my apartment a month ago. I am suspecting that perhaps my apartment is not wired 100 percent correctly, and that this could be causing the problem. How do I test this?

 

[dfuze]

I would suspect that maybe the power supply is dying on you. Do you have access to a spare one to test?

If you think your apartment might be giving you bad power, you should make sure you are using a surge protector (would suggest one anyway)

 

[Bob Ghengis Khan]

I'm using a surge protector. I tested my wall outlet with a multimeter, and it was giving me 121.4 V, I think I can rule that out. I dont have a spare PSU to test, though.

The problem just got worse tonight. I pressed the power button, and the fans started spinning like it was powering up, then everything shut off after half a second. It kept trying to start on its own without me touching the button, and would shut off after half a second every time.

I reset the CMOS, and unplugged the power switch cable to the motherboard and the power connection from the PSU and replugged those in. Now the mobo LED lights up, but the computer doesnt respond to any attempts to turn on. You think this sounds like a PSU problem, and not a mobo problem?

 

[Duncman]

Well...same problem here. I suspect the PS ( I hope) but here is my workaround until I can get a new one:

When I power down I use the soft shut down (Windows "Shutdown"). Then when it is completely off I turn off the P/S (you may have to unplug depending on your P/S), then hit the "on" switch which will discharge the capacitors on your board. Now for start up be patient with what I'm about to say...I've tried multiple combinations and this is the only one that works. When time to start up again, I turn on the PS and WAIT until I see the green light for my ethernet connection. Sometimes it takes longer than other times to illuminate. This light is at the back of my PC where the ethernet cable plugs in. Once it's on I can hit the power switch and it will start up fine. I've had no problems with it running once started...it does great. Here is one wrinkle though. I've found that I have to let it rest for at least a couple of hours in shutdown mode for this trick to work.