Apologies if this is a little long but there's a lot of info to give. I posted a while back about an issue with the video output on my Portable a while back and I couldn't figure it out then so I put it away for a while. So a few months back I just lost video completely on my Portable after a few weeks of it working fine. I bought another video card, tested and working, and that changed nothing. I had my friend test both cards and they both checked out ok. Yesterday I got a 100% working Portable and swapped monitors. The monitor from my first one had a bad cap and the vertical height is way off, so there's one thing wrong. The weird thing is I'm getting the same issue with my first motherboard and the known good monitor from the second. It seems to turn on fine but after a while it gives me 1 long beep and 2 short beeps which I believe indicates a video fault. Exactly the same as before.

Every card in both machines checks out fine, both monitors check out apart from the vertical stretch on the one, 3 video cards are known good and both power supplies are good. What could this possibly be? I'm almost sure it's a motherboard problem now but I have no idea what could cause this. Bad eproms? Some bad chip? I'm stumped.