I have a machine that has been damaged by some careless couriers, and want to replace the damage parts efficiently. I have limited opportunities to test components in other computers, so I'm trying to find out what is broken in other ways.
I have two main issues:
Graphical artifacts. These take the form of small grid-aligned squares which usually appear and then flicker form position to position. If the display driver doesn't crash, they often settle down to a final position, and sometimes the contents of the squares itself changes. This says to me that VRAM is being corrupted. Occasionally there are other artifacts, like polygon spikes, in games.
This is affected by physically pushing on the graphics card: in particular, with the computer on its side, it usually goes away, which strongly suggests a graphics card error. However, it could also be the PCI-e slot or some part of the motherboard.
Twice since the problems started, Windows has somehow been rendered unbootable and unsalvageable: each time some boot files were corrupt and SFC could not fix them (different errors and files each time) so I had to reinstall. The first time this occurred was following a BSOD which occurred after graphical artifacts while playing a game. The second time, the computer BSODed while I wasn't doing anything, but I wonder if it was installing updates.
The thing is, I would quite like it to be the case, for the sake of my wallet, that these are caused by the same underlying phenomenon. So, my question is: is it reasonable to believe that graphics card damage could somehow cause system corruption (presumably by the display driver doing something whacky in kernel mode?) and/or is it reasonable to believe that some other kind of system damage, presumably to the motherboard, could cause very specific graphical artifacts and occasionally more general breakage?
I should say that I strongly doubt the RAM is to blame (since we're talking physical damage and RAM is pretty resilient, and it passes everything but the extreme hammer test in memtest)
I have disabled the graphics card and tested with on-board graphics. This gets rid of the graphical artifacts but does not rule out the slot, or motherboard circuitry related to the card, of course.
I have checked for SMART errors on the disks but there are none. Of course that's not the be-all and end-all. Temperatures are all quite reasonable (CPU gets a bit toasty but it always has) and definitely not correlated to the artifacts or BSODs. I can run furmark/prime95 quite happily for ages with no ill effects. Specific games are more likely to trigger artifacts and driver crashes, presumably because they use the faulty circuitry more.