APG cards won't work on LX chipset mobo

My little brother has a problem with his system: I have a cheap old 440LX chipset mobo (p6alxa?? manufacturer unknown...). It only runs p2's from 233-333, and cacheless Celerons. My main problem though is that it won't run any AGP cards. It boots up, posts, and after a certain amount of time (20 secs or so), the video goes out. So I hit the restart button, and it restarts- the video comes back on, but this time for only 10-15 seconds. The time that the video actually stays on is less and less each time I restart, until eventually it does not come on at all. I have tested this with two different AGP cards- both give the exact same effect. Does anyone have any idea what the heck is going on here?

Is there a setting within the BIOS that allows you to change between which video slot is initialized first? Give PCI and AGP as the only two choices. You will want to choose AGP.

Also alot of the LX chipset boards do not supply enough current to the agp slot for some agp cards.
This was a big issue when the geforce 256 came out.

Setting between PCI and AGP does not make any difference. Also, one of the cards I tested with was an S3 Savage 4, which is known to be a very low-power-consumption card. I still can't rule power out as a possibility, but if it won't run with that card, what would it run with??? I may try some more cards (I have access to a TNT 2 pro, and maybe an old 8 meg ATI card). BTW, the other card I tested it with was the Geforce 2 mx listed in my sig. Thanks for your suggestions, I am not ready to give up on his system yet!

The TNT 2 pro should work ok those were widely used when the lx chipset was popular.
If there has not been a agp card in it before make sure you clean out the agp slot, dust and such can make for poor connections.