Blank screen after boot after video card upgrade

[Jubjab]

I upgraded my video card from a Radeon 9600 to a Radeon HD 3850. Some specs:

MB: Asus P4C800-E
CPU: Pentium 4
GPU: Radeon 3850, AGP 8X, VGA output to CRT monitor via adapter
PS: Zalman 400W
OS: Windows XP

After the switch, I booted up and gor the "New hardware found". The wizard did not find any drivers, so I ran the install from the provided CD and rebooted. This time the screen got blank after the splash, then flickered a couple of times and then recovered with an error message saying something like this "VPU recover has recovered from an error. Hardware graphics are disabled and now instead software rendering". I opened the ATI Catalyst screen and now updated the drivers from ATI's web site. Reboot.

This time the screen goes blank after the windows splash, but does not recover. I tried booting in safe mode, but that didn't help.

Any ideas?

 

[SolMiester]

Is that PSU enough to power that card?....I thought the 3850 was quite power hungry?

 

[Jubjab]

It might be. The box on the GPU states "450W recommended", so 400W might be at the lower limit.

Anyway, I managed to get things working by changing some settings the BIOS. There was one setting for AGP aperture (?), which was set at 64 MB. I now changed it to the max value of 256 MB, and now it seems to work. This is a 512 MB card, however, so I think I will see if there is a new BIOS available which would allow this setting.

Also, I still get an error message after startup from ATI Catalyst, which failes to initialise. It complains about the wrong drivers, wven though I have updated to the lastest.