[PK114]

At first I thought RAM was the problem. I had the original 32MB SDRAM/PC133 in one slot, and had upgraded to 256 in the other. I upgraded to 2 x 256 and all was well for a while. Then more crashes. The screen fills with wondrous patterns of predominently vertical lines - a cross between barcodes and rather loud pyjamas.

For some reason I assumed the CPU was overheating so I removed accumulated dust from the heatsink. Again a atemporary respite, then crashes resumed. I suspect CPU because fiddling around it (for instance removing fan to clean heat sink) seems to be best way of resolving the problem. I would replace it, but I can't remember how to detach it. (It is secured by a narrow chromed strap which runs across it, between the heatsink fins. There are tabs at one end but I can't figure how to press them to release the strap. (The fan is secured on top of the heatsink with screws, not clips.)

Lastly I'm not absolutely sure what motherboard I have. It came with a CD labelled "System Board PC133, V7.85B" and has sound, graphics and modem on board (thouogh I don't use them). Any advice would be appreciated.

[ShadowProwler420]

Are your RAM modules matching speeds (i.e. PC3200, PC2700, etc.) as well as being the same types (DDR, DDR2, etc.)?

And judging by your description of the displays you get, you could have a bad video driver.

As far as your heatsink goes, I recently had to remove one just like the one you describe. I resorted to using a couple flathead screwdrivers to dislodge the bracket from one side of the socket. In doing so, I didn't need to use any leverage or 'pry' the bracket loose. I simply pushed the screwdriver heads straight down until the bracket popped loose. I believe that is the only way to remove those types of fasteners.

In regards to your motherboard, there should be some sort of labeling (either a sticker or imprinted directly on the board) as to what the motherboard's model is. Or there are also a few handy tools out there that can give you overall specs of the machine. A couple that come to mind (which I actually use on a somewhat regular basis) are SIW and SysSpec.

[PK114]

Many thanks. I'll have another go at the heatsink strap. (I assume you appplied the pressure to the spring metal of the strap itself, rather than at one end or the other?

If the video driver is causing the crashes, would that also wipe out all sound and keyboard functionality, which is what seems to be happening?

Regards.

[ShadowProwler420]

If you are having sound and keyboard issues as well as the video issues, odds are it is not video related (although it wouldn't hurt to verify you have updated video drivers anyway ).

What are you doing (if anything) on the system when these crashes occur? Different activities could point at different reasons. However, I'd still focus on your RAM.

[PK114]

The RAM (DIMM/PC133) matches, but only one is new. I might replace the other. Thanks for earlier advice. I got the heatsink off and looked at processor - no sign of overheating. I also established what motherboard I have. The crashes are truly random - sometimes it happens when the PC is doing nothing at all. Sometimes when RAM or CPU is stretched, sometimes shortly or immediately after booting (either before or after WinXP has started) and sometimes after several hours without problems. Anyway, many thanks for some useful pointers. Regards.

[ShadowProwler420]

Are you getting any BSODs when the crashes happen? If so, what errors are being revealed?

[PK114]

Oh dear.... what's a BSOD? LOL

[RogueSpear00]

Blue Screen of Death



Similar looking to that...

[PK114]

Thanks! But no, I don't get those. Just the barcodes.

[ShadowProwler420]

When you had the heatsink off, how did the thermal grease/compound (usually a silvery/grayish colored substance that is put on the CPU to help transfer the heat to the heatsink) look? If it was pretty dry, you may want to wipe off the old stuff and put some new on.

You might also want to check to see if there is an update to your BIOS available.

[dustyjay]

If you removed the heatsink, you would have to clean the old thermal compound off both the heatsink and the processor, then reapply new compound. Failure to do so would make improper heat transfer between the processor and heatsink.

[PK114]

Ah, thanks. I think that could be it. The compound was in four blodges, all of which were solid and hardened, and I'm sure quite useless as an aid to heat transfer. I didn't know why the stuff was there, and of course did not replace it! I was already beginning to rule out RAM as the issue as the PC staggers along with either one of the memory cards in situ, with no appreciable difference in crashes/reliability either way. Also I did update the BIOS fairly recently.

Thanks again!

[dustyjay]

When you clean the old compound off use 90% Isopropyl alcohol or denatured alcohol (avilable from most hardware stores). Do not use the normal Isoprpopyl alcohol you would get at most chain stores which is 70%. It contaains oils and perfumes that leave residue on your surfaces that hinder heat transfer.

[PK114]

Noted, and thanks.

[PK114]

I didn't want to speak too soon, but since following all the advice, I have had no problems at all. Thanks again.