I have totally run out of idea's on this problem I've been having. Completely randomly my computer will show a garbled image on the screen and reboot, it could be whilst playing a graphics intensive GAME or simply browsing on the internet. Also the amount of occurrences are random, some days it will do it several times other days not at all. I can't find a problem with anything and to be honest I've run out of ideas on what to check. I can't duplicate the problem at will and even if I could I have no way of recording what happened.

So far I can tell you what it's not:

An overheating issue (occurs at full and minimum load, also tested)
The graphics card directly [I still believe this to be at the core of the problem, although I don't know how] (I have run stress tests and a memory test all came back good)
RAM memory (stress tested and read/write test)
CPU (stress tested)
Hard drive (sea tools tested and wouldn't cause the problem anyway)

That leaves power, BIOS &/or motherboard, drivers, windows.

Any ideas on how to test a BIOS or what, if any, drivers are causing a problem? Or if anything else comes to mind. (It's my profile computer btw)
My Cmos battery is running a little low, but that wouldn't cause these sorts of problems would it?

Please help, this is driving me mental. Are you protected behind a UPS ( Battery Backup ) so that if you have any dips in power your system is not affected? Guessing you have looked in the bios at the voltages of your PSU to make sure they all look good and hold steady?

In the past I have had mainly power supply or dirty power (lack of UPS) cause reboots, but... the garbled graphics I have only seen in failing GPU's. If you have a spare video card you can try swapping it out, otherwise if your motherboard has integrated video, try that and see if you have different results... However games probably wouldnt run well or at all with integrated video.Forgive my lack of being very instructed in the IT or system units. Just a stab here, for sure. How about running a good malware, spyware, or virus scan? Hope you are not offended by the suggestion.
Den.I agree with [emailprotected]
If you don't find a solution after trying what nixie and [emailprotected] suggested you may want to start a new topic in the Computer viruses and spyware section.
Good luck.
Mike
See if you can divide the problem.
For example, boot the thing with a memory test program and see if it finds anything. It can take hours and hours. The memory test does not need Windows components. If it runs good, that wood indicate that it is not a hardware issue, at least not with the basic CPU and RAM operations.(Replies in no particular order.)

Quote from: [emailprotected] on November 08, 2011, 04:54:43 PM

Forgive my lack of being very instructed in the IT or system units. Just a stab here, for sure. How about running a good malware, spyware, or virus scan? Hope you are not offended by the suggestion.
Den.

I agree with [emailprotected]
If you don't find a solution after trying what nixie and [emailprotected] suggested you may want to start a new topic in the Computer viruses and spyware section.
Good luck.
Mike

See if you can divide the problem.
For example, boot the thing with a memory test program and see if it finds anything. It can take hours and hours. The memory test does not need Windows components. If it runs good, that wood indicate that it is not a hardware issue, at least not with the basic CPU and RAM operations.

Are you protected behind a UPS ( Battery Backup ) so that if you have any dips in power your system is not affected? Guessing you have looked in the bios at the voltages of your PSU to make sure they all look good and hold steady?

In the past I have had mainly power supply or dirty power (lack of UPS) cause reboots, but... the garbled graphics I have only seen in failing GPU's. If you have a spare video card you can try swapping it out, otherwise if your motherboard has integrated video, try that and see if you have different results... However games probably wouldnt run well or at all with integrated video.

Come to think of it this computer has a copy of XP x86, and i think that the problem doesn't occur whilst running that (however I don't run it frequently and even when I do, not for very long periods of time).

My computer (Shuttle SN78SH7, 4 GB DDR2 in 2 sticks) started do something very similar, quite often, and it turned out to be the RAM timings in the BIOS. The SDRAM Trfc setting to be precise. It was set to the shortest time possible 75 nS and I increased it to 105 nS and it's been OK for 6 months now. Some people on Shuttle boards said go further, to 127.5, but I am fine as I am. It seemed thermal related, in that heavy load and/or warm weather made it happen sooner, so I'm thinking the initial Trfc setting was very nearly OK for the sticks I am using and the extra heat was pushing the RAM to the edge. I'm not saying your instability is caused by exactly the same thing but BIOS RAM settings are something to think about especially in a case of occasional instability.