What's causing intermittent video loss?

[trents]

On a customer's machine there is intermittent video signal loss. This is an old AMD setup with Phenom I 9050 CPU and 8 gb of RAM. HD 4650 pcie bus powered video card.

Screen goes black and when restarted the display reports no signal while the computer itself proceeds to boot into Windows.

If machine is turned off and allowed to sit for a time it may boot normally with a video signal but the signal is lost again within a few hours.

Today the customer banged on the side of the computer while booting when there was no video signal. This caused the video signal to be reinstated and it booted right into Windows with normal display.

Here is what I have done to correct and diagnose the problem.

1. Used different inputs and different cables, i.e, vga and HDMI and different monitors.
2. Swapped out the video card with a known good one in that same Radeon HD series. Didn't change a thing. Still got this intermittent video signal loss I have been describing.
3. Ran the Windows Memory Diagnostic which reported no issues with RAM.
4. Checked the smart drive info. No issues reported dealing with the hard disk. The disk is just few months old. You would think disk issues would
5. Stressed with Prime95 blend and for 20 minutest with no errors. So putting the machine under stress does not produce the problem.
6. Right now I am checking for Windows file system integrity with sfc /scannow. Don't expect to find anything.

My guess is this is a CPU or CPU socket problem or a motherboard problem. Maybe a damaged CPU pin or a bad trace in the PCI-e circuit somewhere.

Can't be a video card driver issue as that would not cause no signal pre windows during the boot up.

Any ideas?

Edit: no integrity violations reported by sfc /scannow

 

[EarthDog]

Yes... bake the card.

Or... replace it. Dude just needs an image on the screen not game, right? Cheap simple fix.

Edit: you swapped gpus and it still happened?? Hmmm... slot going bad perhaps? Try a different slot?

 

[trents]

I didn't trust the motherboard/CPU so I put new components in. This is for a print shop business and it needs to be reliable for production.

 

[trents]

I put the motherboard/CPU/RAM from this problem build in a different build and it seems to not to have the video issues I reported in post #1. I'm thinking there was some kind of driver or software conflict with the printing shop production software the customer was using.

 

[habbajabba]

Replaced the monitor?

 

[trents]

Replaced the monitor?

Yes. I listed that in point #1 in post #1

 

[habbajabba]

Oops. Possibly just an old cobbled together build perchance. Gremlins. Work pc's tend not too get the tlc they all need at one point or other. Dust accumulation who knows. I had an older NEC crt wherein it's power supply was not soldered correctly anymore from heat fluctuations. Ended up having to just toss it. There's definitely something to be said for no moving parts and low power requirements.