I bought 3 Gigabyte GA-7ZX motherboards. One of them is working fine. The other two have the same problem, but to different degrees. All are running Windows 98 Second Edition OEM, with Duron 600 CPU’s and 128 MB PC-133 RAM.
The problem occurswhen the system is shut down, using Start | Shut down | Shut down. Each system shuts down correctly. If the system is restarted by pressing the power button within an hour, it restarts correctly. But if the system remains shut down over night, itdoes not respond at all to the power button. The only way to restart the system is to remove power completely for a minute or two, then re-apply power and the system will respond to the power button again.
This happens all the time on one system, the other system will restart correctly about 25% of the time.
I have put the system which never restarts after being off overnight on a UPS, thinking it might be a power problem. This did not change the situation. The BIOS revision on this system is F8. There is no way to disable Power Management on this motherboard that I can find.
What might be causing this?