locks up w/512 not 256

[ramslam]

I've had this FIC-748 mobo for 10 months running 512m 3200/400 memory with no problems. A few weeks ago my son was playing a marathon game of a demo of Rise of Nations and then tried to load a demo of Perimeter and the computer just stopped-black screen. Occasionally when trying to re-boot there would be a series of long beeps which don't seem to be anything Phoenix describes.
I thought it was a memory failure because when I replaced it with a 256m mem board the machine booted and works fairly well. Then I bought a replacement 512m 2700/333 mem board and again the black screen no-boot-nothing. Can't even get into CMOS with either 512m board installed.

Anybody got any ideas?

System:
2600 Athlon Barton
FIC KT-748
ATI Radeon 7500
Phoenix BIOS 6A711F0AC-00

 

[xeenrecoil]

heya ramslam;

You could try resetting c-mos, there might be some kind of wierd stuff going on in the bios. Considering you have already tried a different module, and it works with 256MB its likely a bios glitch causing the problem.