Randomly the Computer won't fully power up

Microsoft Windows 7 home premium - 64-bi...
January 28, 2011 at 17:53:01
Specs: Windows 7, INTEL Dual Core 6700 / DDR2 850
After shutting down using Win 7 64 bit and you want to restart... when you press the power on button on the ATX box the fans start but that is all that happens. After I turn off the main power to the PSU, the computer will start fine with the ATX power button. I have chk'd all of the cable plugs and made sure they were securely seated.

System Info:
Phoenix Award BIOS 6.00 PG
INTEL6700 Dual Core 2.67
SATA WD Raptor HD - brand new (old ones started failing)
650 or 700W SLI PSU (ANTEC or OCZ?)
2 GB RAM Kingston HyperX DDR2 850

I built this system in Early 2007. So my concern is MB or PSU issues. But since it starts after I reset the Main PSU, I am wondering if something in windows 7 is not completely shutting down the MB?

Thanks for any help in localizing this issue. I don't want to build and entire new system if I can replace one part. If it turns out to be the MB... well, then I'll go for the gusto move up.

See More: Randomly the Computer wont fully power up

Report •

January 28, 2011 at 18:05:18
If you are having to flip the switch on the back of the power supply that would be the place to start.

Report •

January 28, 2011 at 19:39:42
I am with worldlibrary on this one. I would be thinking the power supply is failing. I have had to personally that would still power all the fans and lights one of them even spun the hdd. Neither supplied enough power through the mb though. When checked with a volt meter one was a steady 8.4 volts and one fluctuated between 4.7 and 9.3 volts.

Do you have to flip the switch on the power supply every time or is it random as the subgect line suggests?


Report •

January 28, 2011 at 19:56:55
Flipping the PSU switch seems to cure it most of the time... I haven't established the pattern yet. I figured I would have the PSU chk'd out as a starting point. But since it appears to work when I reset the main PSU switch I thought it might be a software glitch between Win 7 and the MB. I just installed Win 7 and then this started to happen.

Report •

Related Solutions

January 29, 2011 at 10:14:38
Computers have a power controller. It decides whether to let power stay on, let the CPU execute, let the BIOS be read, how to shutdown a computer, etc. To know what that controller is doing and why means a digital multimeter. A tool that costs less than a good hammer. And that is sold even in most hardware stores. You cannot see anything from a pattern or by inspection. You can only 'see' with the meter.

In your case, a meter on a 20 VDC scale must measure six wires from power supply to motherboard. The purple, gray, and green wires are touched with a meter probe both before and as the power switch is pressed. Read and post those three digit numbers. Do same for any one red, orange, and yellow wires only when and after the power switch is pressed.

What results is an answer without any speculation. Without any more 'it could be this' or 'might be that'.

Report •

Ask Question