Presario 5900z - trying to upgrade video card
 

I have a Compaq Presario 5900Z with Athlon 750 processor running Win98.

It appears my original video card is dying, I'm getting large vertical lines
of garbage down the screen in all modes, including the Compaq splash screen.
Moving the cursor effectively obliterates anything it passes over. If anyone
thinks it could be something else, let me know.

The machine came with an Nvidia 32 mb 256 AGP card. The cooling fan on the
card is not working (don't know when that may have stopped).

I purchased an ATI Rage 128 Pro 32 mb AGP (CompUSA P/N 293591) card to
replace it. When I rebooted the machine after putting the new card in, I
never even got a signal to the monitor and the machine did not go through
the normal boot process (judging by the HD activity lights). I swapped the
original card back in, and through the video hash, changed the driver to a
basic VGA 640x480, as suggested by the manual if there was problem. Same
result.

There doesn't seem to be a bios upgrade for this model on the Compaq support
pages. I am at a loss. Any ideas?

Thanks...