HPd530 sff - freezes with blocked screen pattern

[mcbmcb0]

hello

my HP d530 sff (P2.66G, 512 ram) freezes occasionally with a strange blocked screen pattern - like psychedelic colored chessboard squares on a blue background. The squares shimmer a little (impying some procesing?) but the system is totally unrersponsive. The fault appears randomly, and does not appear related to how long the machine has been run, nor its current task (as far as I can tell).

It runs xp pro. I've reinstalled xp on a different HDD and get the same, making me think its not software/drivers. I've upgraded the BIOS, run memtest 86+ and prime 95 for hours and some Inquisator and Ultimate Boot CD hardware tests. They are all fine, making me think the basic hardware is OK. I considered the onboard video but I can play movies over a network which is pretty intensive.. With the lid off nothing in the box gets too hot to touch tho some chips and caps must be near 60 degrees celcius. CPU heatsink fine to touch.

It would be easy to give up and say its a wierd motherboard fault, but before I do any ideas? The software keyed to the machine has more value than the box so I'd rather not throw it away.

Thanks for your ideas, Mike

[longscope]

I had a videocard that did that when it was going bad, but it really only happened after I was playing games.

If it's an onboard video, see if you can borrow a videocard from a friend and see if does the same thing with theirs. If not, you know it's the video.

[Suspishio]

What's changed on your system? Like the screen? What screen is it? The usual non-malware suspects are (some of which you know):

1 LCD screen firmware
2 Glitching along the VGA (?) cable (or is it DVI in your case?)
3 Change of screen without update of video driver
4 Might need a driver for the particular screen

You could check (in the VGA cable case) that the cable doesn't pass over any mains cables that might suddenly be poked into live - like a printer mains cable which propagates RF when switched on. Or indeed if it's a CRT monitor, the CRT cable. If the CRT is old, there may be arcing. We prolly don't know enouh to properly diagnose at this stage.

You can (maybe) check if the PC itself has frozen by hitting a key and waiting for the clicks when it reaches the buffer limit. It makes a difference to know if it's the PC that's frozen or just your screen.

[mcbmcb0]

thanks for the replies

i updated all drivers including video and monitor drivers - no change. i disabled parrellel and serial ports in the bios - no change. i added an agp card which disables onboard video (i checked it is disabled in bios) - the only change is when it freezes there is no strange pattern on the screen suggesting the weird video pattern was not significant. It definately freezes - repeated ctrl-alt-del gets no beeps and num lock doesn't work on the keyboard. i've had the memory modules in and out, with one then the other - no change. there are no events (of note) in the event viewer which i take to mean its liekly hardware (?).

any further ideas....???
Thanks

[Suspishio]

We're here and you're there so we can only go on what you say.

On that basis, I'd say that the motherboard or CPU are glitching through age and electrical breakdown of sorts. A misbehaving capacitor is enough to do this.