[jasen357]

To begin:

Running winxp with service pack 3.

OCZ stealthXstream 600w PSU (OCZ600SXS)
ASUS motherboard (m4A785-m 785G R)
CPU AMD ATH II X2 250 AM3 3.0G RT
2 gigs of kingston ddr2 ram: (khx8500D2/2G)
500 gig Sata hdd (samsung hd502HJ)
all in an old dell case

I recently put this machine together for my sister as a birthday present. It powered up and ran fine. However, after being shut off for several hours overnight, it would not turn on again. I can clearly see the motherboard LED is not lit.

To get it to run, I have to unplug the machine for several hours, and once it is replugged, the LED is lit and the machine turns on and works great.

It seems as if the PSU runs out of juice after a several hours of sitting unused and still plugged in, if that makes sense


Any ideas?

Thanks in advance

 

[gcavan]

Do a "nuts and bolts" maintenance on the computer. I mean go over the insides and confirm everything is plugged in firmly.

Here's something that may sound off the wall. Your psu has four 12 volt rails. 12V4 is dedicated to the video card auxilliary connector. As you don't list a graphics card, I assume you are using the onboard. I wonder if the supply has a "minimum current draw" spec for the 12 volt rails.

Edit: The techinical spec sheet here does state minimum 0.1 A on 12V4.

Let's assume, for the moment, this is the case.
Easiest way to test it - temporarily install a low end PCIe video card.
If that is not possible, you would need to fool the power supply into believing there is a card installed by jury rigging a small load (any standard fan or a 100 ohm, 2 watt resistor) on the 12V4 line,

 

[jasen357]

I like the idea! I'm about to try it out, although I stupidly didnt give the rest of my specs. I also have her old 250 gig IDE hard drive plugged in along with a dvd combo drive, both of which should be sucking up power I'd think. I'm still going to try using my Pci express card and see if that helps

 

[jasen357]

The motherboard still isn't getting power, even with the pci-express card installed. I don't get how the computer can work for several hours, then all the sudden lose "charge."

Any other ideas?

 

[Tyree]

If the PC isn't getting any power the problem has to be a power issue.
Is the OCZ PSU New?
I would suggest bench testing.

1) Remove EVERYTHING from the case
2) Set the motherboard on a non conductive surface. The motherboard box is perfect for this. DO NOT PLACE THE MOTHERBOARD ON THE STATIC BAG! It can actually conduct electricity! We are going to try and assemble a running system outside of the case.
3) Install the CPU and heat sink. Intel Guide AMD Guide
4) Install 1 stick of RAM.
5) Install the video card and attach the power supply connection(s) to the card if your card needs it.
6) Connect the monitor to the video card.
7) Connect the power supply to the motherboard with both the 24pin main ATX Power connection and the separate 4 or 8 pin power connection.
8) Connect power to the power supply.
9) Do NOT connect ANYTHING else. Make sure you have the power connector on the CPU fan connected.
10) Use a small screwdriver to momentarily short the power switch connector on the motherboard. Consult your motherboard manual to find which two pins connect to your case's power switch. Then touch both pins with a screwdriver to complete the circuit and boot the system.

If all is well, it should power up and you should get a display. Then assemble the parts into the case and try again. If the system now fails to boot, you have a short in the case and need to recheck your motherboard standoffs.

If the system does not boot after this process, then you most likely have a faulty component. You'll need to swap parts, start with the power supply, until you determine what is defective.

 

[jasen357]

yes the power supply is new, and i'm wondering if in the dell case something could be shorting. Would that cause it to work after its being unplugged for a while? But not after being plugged in, started, and then shut down?

 

[Wrench97]

Try a different Power Supply.