No Video at POST, but Normal Once in Windows

[Fragmire]

I have a motherboard with on-board video (Intel 945G), but uses an ATI 9600 Pro on the AGP slot connected to an LCD panel via the DVI link. Started a few months ago, I would get no video signal at all until the system boots to the Windows welcome screen. Some more experimentation showed:

- the D-SUB output on the video card doesn't have signal until Windows welcome screen
- if I remove the video card entirely (thus enabling the on-board video), everything is normal and I get signal from boot through the on-board video D-SUB out
- no video signal from the on-board D-SUB out while the AGP slot is occupied (expected behavior)
- changing the BIOS video priority (AGP vs. on-board vs. PCI) has no effect

I don't recall having done anything special when this started happening a few months ago.

Any idea? Could it simply be due to aging hardware?

Thanks.

 

[Fragmire]

Some updates from more testing:

The problem seems to lie with the video card, though I'm not sure exactly how. This is what I did:

- Tried another video card (Radeon 9800 XT) and was able to see everything from boot all the way into Windows
- Tried another, much more powerful power supply, but didn't affect anything
- Tried my video card in another system and was able to see everything from boot all the way into Windows

I'm not sure if there is somehow some kind of incompatibility between my video card and my motherboard / BIOS, but I don't recall having flased the BIOS around the time this started happening. At this point, I'd appreciate any kind of suggestion or guess.

 

[mobobuff]

The proper drivers aren't loaded until Windows loads? I've seen this before.

 

[Fragmire]

Does this mean that the BIOS for some reason cannot recognize the video card? If so, how can I fix it?

 

[Fragmire]

[moved to Video category]
http://forums.anandtech.com/messageview.aspx?catid=31&threadid=1902243