Working Computer Stopped POSTing - Unusual Problem

[refresh daemon]

Computer Specs:
3.2GHz Intel Pentium 4
ASUS P5GDC Deluxe Mobo
2x 512MB Crucial DDR2 RAM
XFX 6600GT Video Card
Forton 530W PSU
Antec P160 Case

The computer ran fine for a bit over a year. I was working on typing up a doc in MSWord when the computer suddenly turned off. Would not start when the power button was pressed. I opened up the case and I noticed the mobo light was on. When I turn the PSU off and on, and press power, the fans twitch but no spin up and no POST.

So my immediate thought is bad PSU. I grab a friend's working Fortron 550W PSU and hook it up. Same problem. Both PSU's also respond to shorting.

Okay, then I tested for EMI/grounding problems by dropping the bare computer (mobo, CPU, RAM and video) on a cardboard box and did the whole screwdriver to start the power. Same problem.

Randomly, I decided to remove the XFX card. The fans spin up. After some more testing, I found that with everything connected except the XFX card, all the components "appear" to be working, including hard drive spin up, keyboard responds to button presses (capslock and numlock), mouse's LED lights up. Of course, without a display, I have no idea if it's working or not and the P160 doesn't have a PC speaker so I can't listen for error beeps.

Anyway, I figured that maybe it's the graphics card, so I borrow an old Voodoo3 PCI card and plug it in. Everything starts up as w/o the XFX card, but no video signal from the Voodoo3 card. So now I'm thinking it's not the graphics card, but the mobo--maybe something related to the PCI died.

I RMA the motherboard to ASUS and they send me a new motherboard. I hook everything up, thinking that it's going to work. But no. Same problem. I repeat all the previous tests and the same symptoms occur. Now I'm thinking a few things:

1) PSU is fine. Tested on other machine and other PSU fails to start mine.
2) Mobo should be fine--since I got a new one and it has the same problems as the last one. However, if another component broke the motherboard, it's entirely possible that my new one got similarly busted--but I think this is a long shot.
3) It's possible that both graphics cards are toast (the Voodoo3 is pretty old). I'm going to test the XFX card on my friend's system and see if it works.
4) It could be the CPU, but if it was, why would the computer not start up w/ the XFX card and start up and spin the HDDs and flash the IDE light w/o the XFX card?
5) Can memory cause this problem? Just Mobo, CPU and videocard and no memory has the same effect as with memory, so I'm inclined to this that my memory is fine.
6) I highly doubt it's the HDDs or the ODDs since the machine would still POST if it were.

Any thoughts? I'm going to test the graphics card on Monday and will get back with the results. I find it really odd that it seems to start up fine w/o the XFX card but won't start up at all w/ it. And that the Voodoo3 card does nothing--although the computer still gets going without video.

I'd love your input/advice. I really don't want to have to gut and rebuild the insides of this machine so soon after building it. (And I don't want to spend the $$$).

jc

 

[Nahlidge]

Always a possibilty that the new motherboard they sent you is DOA. I doubt it's the video card because it doesn't really make sense that the computer just flat out won't turn on if it was bad (though who knows). The memory same deal, it would more than likely boot up and then re-boot when Windows begins loading or something. CPU is a possibility but if it was that I would think that the computer would at least boot up, but not even make it past the initial post.

Best bet would be to use a friends video card, if same problems occur I would say it's the motherboard or the CPU (since you know the PSU is fine). Does your friend have a CPU you can test with as well?

 

[refresh daemon]

After some web research, it looks like others have had similar problems, but no one posted their resolutions. If the graphics card is bad, it's an easy fix. I'll bring my CPU to test in my friend's machine as well--maybe if it doesn't work, the problem will be found. If both are found to be operative, then I guess it's RMA x2. Thank God that I have a laptop to work off of in the meantime.

 

[refresh daemon]

Here's an update:

I tested the XFX 6600GT on my friend's computer and it did the same thing to his computer. No POST. His machine was an AMD-based machine too. His XFX 6600GT does work, so it's pretty clear that it's the videocard. I'm going to RMA it with XFX, who thankfully has a lifetime warrenty.

But it can now be said that a bad videocard (at least a PCI-E card) can prevent a computer from POSTing. It's not always the motherboard or PSU.

jc

 

[JeepinEd]

Originally posted by: refresh daemon
Here's an update:

I tested the XFX 6600GT on my friend's computer and it did the same thing to his computer. No POST. His machine was an AMD-based machine too. His XFX 6600GT does work, so it's pretty clear that it's the videocard. I'm going to RMA it with XFX, who thankfully has a lifetime warrenty.

But it can now be said that a bad videocard (at least a PCI-E card) can prevent a computer from POSTing. It's not always the motherboard or PSU.

jc

Be sure your PSU is working properly.
I had the exact same problem. I figured out it was my video card, so I replaced it. Everything worked fine for a while, then the same problem reappeared. It turns out that my PSU was killing my PCI-e video cards. I went through 2 cards before I realized the problem.

 

[refresh daemon]

Good call JeepinEd. It's a good thing I have an electrical engineer as a roommate. He has all sorts of electronics equipment; so I think he'll be willing to help see if the voltages are correct on each rail.

jc

 

[refresh daemon]

The 6600GT has been RMA'd. Let's find out what happens when it gets back. Will the saga continue? Will it come to a close? Oh, the drama!