Video becomes flashing squares, PC freezes

I am computer tech, solve this kind of probs all the time.  
But this problem has gone for about a year now:

45 PCs, all IDENTICAL hardware -P4,128ddr- & software -win98- (its a school)

Supposedly (never seen it) PC freezes & video on monitor becomes corrupt, turns into this multi-colored pattern of flashing tiny squares.  
I am not absolutely sure if background is completely black or if it remains last thing on desktop.

This is what Ive tried:

1. Updated drivers

2. Changed settings on bios, mainly shared memory resources, irq assings for vga, etc.

3. Checked for overheating , installed extra fans.

4. No electrical probs.

And lastly:

5. Changed motherboard (on 1 pc). Of course diff. vendor.

Oh, PC can freeze just about anytime, for no particular reason whatsoever. Reboot and all is ok, same PC will not necesarily fail again, at least not in the same day, week or month.  

2 PCs can fail at the same time (or not) and maybe none will fail in a week or 2.

See why I am going nuts? If you have any ideas or want more info please ask.

Who is Participating?

Improve company productivity with a Business Account.Sign Up

Wolfpup99Connect With a Mentor Commented:
Are you saying this can happen on any of those 45 PC's?  

Very strange indeed.  What kind of video adapters are they using? -- I would guess it's something integrated into the motherboard.

The symptom sounds a lot like failing video chipsets; it seems unlikely to be happening to all of them but it might be a systemic problem like a bad or marginal batch.  If the video problems are seen while using 3D accelerator features of the chipset (as in playing video games) it would tend to support this theory.

You might want to consider doing a test with an inexpensive add-on video card for one or two of the PC's, if you can disable the on-board video via hardware or BIOS.  WinXP could also do it at the OS level but I'm not sure about Win98.

It might also be a problem with the video drivers; I know you said you upgraded to the latest but that doesn't mean they're problem-free, especially if it's a chipset that's no longer supported.  Switching video adapters would eliminate both the video hardware and software as a possible cause.

What make are the PC's?  Any hope of getting some advice from the manufacturer?
alcantar06Author Commented:
never heard of it, huh?
now you know how I have been feeling for the last year :(
alcantar06Author Commented:
Well manuf. said it was probably overheating, but no good because installed extra fans in some units, and also monitoring program, everything seems to be working ok, still this problem appeared now and then.

Yes it is onboard vga. S3 graphs i think.

Actually I replaced 1 motherboard, switched manufacturer, still had onboard vga but another chipset.  And the problem did not present itself in that machine for about 3 months, so I thought finally solved it, and when we were getting ready to switch all 45 mb, there you have it. :) lucky we

yeah we had thought of using inexpensive agp cards but first we went to the mb switch, which seemed to work fine. not.

so maybe i will follow that advise and, at the same time will change some to xp.

and finally, yes, it can happen to any of those 44 (not 45 my bad) and, for all i know it can happen when running ANY app, ANY moment.  Not necesarily a game or something, after all its a school.

Or hell, maybe they ARE running some kind of f***d up game but since it would be against the rules they "forget" to mention it. How can i do my job then??? (sobs)
Get expert help—faster!

Need expert help—fast? Use the Help Bell for personalized assistance getting answers to your important questions.

burrcmConnect With a Mentor Commented:
Try disable hardware acceleration in Video performance setting. Will free up resources and make card work less. No good for games, but Office etc OK. Might fix it. Weird that different board has same prob though. Last time I saw a screen like that was a Commodore 64. What version of DirectX are you running? Might be best to stick to original 98 version. 6.1 I think.

Chris B
Actually since different board had same prob. maybe its the monitors?? Are they all the same type? Set refresh low - 60 - 65 so they can take it easy.

Chris B
ridConnect With a Mentor Commented:
I was thinking about weird screensavers, perhaps something unusually badly written that takes down the O/S...
alcantar06Author Commented:
thanks for all the great ideas!

chris:  I think I already tried disabling accel., i really cant remember.  And no directx installed in those machines.

chris2: ok ill try the refresh rate.  yes, all monitors the same.

rid: no, screensaver is win98´s , and if i´ve understood correctly, it fails while working.  The machines dont have internet so no spyware, etc.
worth checking out, though.

I will make some changes and wait for feedback, there are plenty PCs so i can make all this changes at the same time.  Please check back to see results. This might take a while.

And please continue to apport ideas. thanks!
alcantar06Author Commented:
more info:

One of the machines has died.  Onboard video has stopped working, monitor displays nothing but light is green, you can tell everything is working fine, windows runs, etc.
On an older monitor, video is sent but corrupted (like when vshift is out of sync, and everything is bigger)


Lots of errors have begun appearing, mainly video related errors, like "error in GDI", "error in 3D objects", when closing powerpoint, etc.

I still havent had access to the boards, maybe this week; will try all suggestions.  Thanks.
alcantar06Author Commented:
It seems the problem was with the OS .
All machines have been running winxp now for like a month and we' ve had no complaints.
I still feel it is early to say this is over, but I really hope it is.

I did all of the suggested but nothing I tried helped, sooner or later the problem reappeared. (I did finally see it).

As for the new MoBo that had the same error, the chipset was the same (onboard prosavage).  Though I really doubt THAT motherboard DID fail, it is a possibility due to same chipset. So: Beware of win98 when using onboard video. Specially S3 Prosavage DDR.

That said, I think the fair thing to do is split points.  Please post your thoughts and comments all that are still following.  I appreciate your help.

P.S. Oh yeah, another mobo lost onb vga. I hope that stops now.

No comment has been added to this question in more than 21 days, so it is now classified as abandoned..
I will leave the following recommendation for this question in the Cleanup topic area:
Split: Wolfpup99, burrcm, rid

Any objections should be posted here in the next 4 days. After that time, the question will be closed.

EE Cleanup Volunteer
Question has a verified solution.

Are you are experiencing a similar issue? Get a personalized answer when you ask a related question.

Have a better answer? Share it in a comment.

All Courses

From novice to tech pro — start learning today.