Graphics card randomly placing lines

[DaveSW]

I have an Geforce 4 Ti4200 128mb card.
I recently decided to disconnect my extra case fan at the back.
It has worked normally for a few weeks.
Yesterday when I turned it on, it got some way towards loading windows (I saw it at the grub bootloader stage) and the went black. I reset it, And carried on using the pc.
Then I loaded up Commanche 4, and after a while the screen started getting garbled - most of it was there, but in places pixels from other parts of the screen were being displayed. Then the system froze.

I opened the case and it was rather hot inside, so I reconnected the case fan and let it cool.
Today the same thing happened, it just lasted much longer before it started getting garbled. The air exiting the back of the case is still fairly cool.

I have preiously modified the airflow slightly by removing two pci covers to allow cool air in at the back by the graphics fan. Placing my hand over these I can feel an inflow of cool air.

Is my problem a cooling one, or is my graphics card just dying?
I've reinstalled drivers and it's still the same.

[Catweazle]

Are you sure that the fan on the card isn't 'dying'?

Have a good look at in operation. It's not enough to simply see the thing spinning. BE sure that it's actually spinning at the correct speed, and not visibly slowing down during use.

Alternatively, the thermal paste between graphics processor and heatsink may be in need of replacement. That's a rather tricky job, so it might be one for a technician if you are not familiar with the task.

[DaveSW]

Hi Catweazle
When I checked it, everything was spinning nicely (more spin than labour in fact!!).
I dismantled all the fans and heatsinks and hoovered (technically Dysoned) them till they were free from dust.
So I loaded up the machine again and it died outright.
I rebooted and it ran nicely for two levels, then froze on the third. I glanced inside at the fan, and the graphics card fan was on stop.

I'll check all the connections etc, but maybe it's time for a new cooler in there.
I'm also reworking the airflow through my case (it's a cheap old mercury one).

Which brings me to two new questions:
1) Would you reccomend any of these VGA cooling solutions?
http://www.mpcomputersdirect.com/Shop/Products_Sub.asp?PC=20&PSC=2346
and
2) Do you know any suitable, freely available materials for dust filters?

[Catweazle]

You'd have to locate a local supplier, but I'd recommend this one:
http://www.pccasegear.com.au/prod1603.htm

I'd also INSIST that you use this thermal compound:
http://www.pccasegear.com.au/prod227.htm
(White, silicone based stuff is crap!)

Dust filters are not expensive. I'd pay for them ;)

Most of all, I'm worried that the old paste was not adequately cleaned, which would make temps rise instead of fall. Follow the instructions here, regardless of what paste is used:
http://www.arcticsilver.com/arctic_silver_instructions.htm

[DaveSW]

Hi Catweazle
Thanks for the tips and reccomendations.
I've found a few companies selling them, so maybe I'll order one. In the meantime I got the fan up and running via an alternate connector, so we'll see how it goes.
Cheers
Dave

[DaveSW]

Hi again
All the fans are running normally, and I've added more case fans to get more airflow. I've also cut away the pressed steel grilles and replaced them with thermaltake grilles.
But the computer is still freezing up...
I left it for a while, then booted to windows. I spent an hour looking at a pdf, but within 30 seconds of launching comanche it had frozen and brought up those lines again. The graphics card fan was running smoothly when I then looked at it.
Did it just die when asked to do some work?
Is this a problem with cooling? - the heatsink seemed cool enough when I touched it. Is it perhaps a different chip that isn't cooled, used by comanche - e.g. hardware T&L? Or is it more likely to be permenant damage to the card?

Should I spend £19.06 on the Artic Silver solution, or just get a new card for £18.57?
http://www.mpcomputersdirect.com/Shop/Product_Details.asp?DP=9753&RP=0&BSP=0
Or a 9600LE for £37?
Your thoughts appreciated!

[Catweazle]

Both of those cards are a significant downgrade compared with the Ti4200. If you are going to replace the card it is not a good idea to purchase one which is less powerful.

I would consider a format/reinstall before deciding to replace the card. It could also be a software corruption (drivers perhaps?) problem, and I'd want to be sure to eliminate that possivility before spending money. Format and clean install is the ONLY way to positively eliminate software causes.

[DaveSW]

Yes it is a downgrade, but I only use this system for web design and playing comanche - never anything more demanding than that, so I wouldn't have thought I'd notice the difference... would I? Comanche runs smoothly using onboard graphics, so it's not all that demanding.

With the drivers, it happens right from the very first screen - the bios settings etc. It also happens in Linux (I have a multiboot) which uses a different set of drivers which I haven't reinstalled. Would that be equivalent to a reformat?

[Catweazle]

If it's happening at the BIOS screen I'd have to think the card is kaput!

[DaveSW]

Thanks Catweazle - guess I should have mentioned it earlier!
I think I'll go for a cheap Radeon to tide me over the exams, then splash out on something after my exams!

[Real-tiner]

Sounds like bad RAM in the video card to me - or a bad video controller chip.

Or the card may not be seated in its socket right.

Overheating during the brief disconnection of the fan may have caused permanent damage.