Really Strange Behavior in BIOS / boot

[badinplaid19]

Hey all,
I work at a university and build rigs for graduate students in my department. One particular machine is behaving very strangely. It gives a single beep (system OK) and posts just fine. When I enter the BIOS, all voltages and temperatures appear stable, and all the RAM and both hard drives are recognized. Sometimes, shortly after checking all of this, the machine powers down. Other times, I'm able to boot up Windows 7 and get to the desktop before the machine decides to shut down. I swapped out the power supply with another, identical unit from a working PC and had the same issues. I also put a new, identical motherboard in, to no avail. Any thoughts? (specs below).

MOBO: Gigabyte GA-970A-UD3P R2
CPU: AMD FX-9590
PSU: Corsair CX600
Video Card: EVGA GeForce GT 610
RAM: 32GB G.Skill RipjawsX

(Let me know if you need more info, I'm still new at this).
Thanks!

- - - Updated - - -

Also, just for argument's sake, this machine functioned fine for over a year, and there is an identical machine in the same office that continues to function without any problems.

 

[ATMINSIDE]

Is it giving any error code and/or BSOD or simply going blank?
Have you checked the PSU voltages with a multimeter?
What cooler are you using?

 

[TechWizard]

CX series is the lowest Corsair teir of PSU. I'd get a PSU tester if I were you to rule that out first. Typically if a machine is randomly powering down it has to do with power and not so much with anything else.

Edit: I just noticed you did swap the PSU with another. I'd still test it, but I like being 100% sure.

I'd also look to see if you can update the motherboard BIOS if the PSU ends up testing OK.

 

[badinplaid19]

It just goes blank. Sometimes, the computer stays powered on but the monitor says "No Signal." When that happens, the machine has to be turned off at the power supply, because holding the power button down does nothing. I haven't checked the PSU voltages with a multimeter, just read the outputs in the BIOS. Again though, I don't think it's the PSU because we swapped the exact model in from a functioning computer and had the same issues. The cooler is a Cooler Master Seidon 120XL Liquid Cooler with 2 fans.

 

[Johan45]

Have you tried swapping the GFX card?

 

[TechWizard]

Have you tried swapping the graphics card?

I was going to suggest taking out the GPU and running solely on the CPU's rendering capabilities... but after checking out your motherboard it doesn't look like you have any video outputs.

This is very strange issue to have that is generally harder to diagnose. Unfortunately, it's just one of those things you will have to troubleshoot until we can figure out precisely what is causing the issue. I've seen this quite often over the years and it usually comes down to the PSU or video.

If you can get into Windows I'd check the system event logs, see if you can dig up anything in there related to video drivers or driver state power failures.

Edit: I'd also suggest removing any extra peripheral devices if you haven't already, I figure you've done this because you've replaced the motherboard, but I'd rather state the obvious than assume and find out later it's a USB device or extra PCIe card.

 

[badinplaid19]

Haven't tried swapping the GPU yet, but this last time I tried to boot it up, it posted, went into the BIOS, and temperatures were upwards of 75C. I wonder if the pump on the water cooler is on the fritz? Seemingly random power downs could be the result of a jammed pump, right?

 

[TechWizard]

Random power downs could definitely be a result of overheating. The system has fail safes set in place to prevent it from harming itself in the event it gets too hot.

 

[Johan45]

I was going to suggest the pump. put your hand on it and see if you feel anything

 

[ATMINSIDE]

Whoa 75°C in the BIOS?? THAT is your problem for sure.

 

[badinplaid19]

The pump is wicked hot when the machine is powered on. The pipes both get hot, but the radiator doesn't seem to...

 

[wingman99]

I would check for a electrical short also unplug everything that you don't need to boot into BIOS and see if it will shut down in windows or bios.

 

[Johan45]

Almost sounds like the pump to me.

 

[ATMINSIDE]

The pump is wicked hot when the machine is powered on. The pipes both get hot, but the radiator doesn't seem to...

Pump is shot.