I have had constant problems with my 663AS Ultra mobo (w/ Athlon 1.4ghz) for almost 2 years. Every time I fix it it will work for a while and start acting up again. It constantly restarts or hangs. Its not a software problem because it often freezes at POST or when I'm in the BIOS. I've replaced all the hardware with other working parts and still the same problems. It's definately the mobo thats the prob but I don't know how to fix it. I've updated the BIOS and tried numerous different settings. I also bought a brand new 400w PSU. Increasing the voltage to 1.8v seems to help a bit but it still restarts or doesn't start at all. Decreasing the FSB to 100mhz seems to work (i think, its hard to tell because often it works fine for a while), but I don't want to run it at 1050mhz (the multiplier is permanently set to 10.5). I've tried everything I can think of...does anyone have ANY suggestions?? Now I'm thinking it is a heat problem...but it worked fine for the first year that I had it. Maybe I need to replace the thermal paste and get a better cpu fan? Thanks.

400 watts means nothing if the amps aren't distributed right across the various rails. The +12v rail amperage is critical. The recommended minimum is 18 amps...more if you have multiple HDDs, optical drives, cooling fans, high end video card, etc. It could be an overheating problem, but replacing thermal material is not "routine maintenance"...that is, it's not something that normally has to be replaced once it's properly applied. Check the temp readings in your BIOS. The Athlon tbird tends to run very warm.... Have you tested your RAM? Try downloading memtest86...create a bootable floppy & run the test for at least one complete series. If you get any errors at all, try swapping out the RAM. http://www.memtest86.com Asus A7N8X-X 1800+ @8x210mhz 512mb PC3200 Ti4200/8X 128mb WDC 60GB

Tested the RAM and its fine. The temp readings are usually around 45-60C for the CPU and 25-35C for the system. Its always run pretty hot. I've had a small house fan blowing directly into the case for 2 days and it hasn't restarted....so I'm fairly certain that heat is my problem now. I don't think the heat is being drawn off the heatsink well enough...its always very hot to touch.