We have a Gateway 980 Series server running Raid 5, Windows 2000 Server, 2 GB RAM. The server started locking up about once a week. Sometimes it would just freeze on the desktop screen and the mouse and keyboard functions would not function. Other times the monitor screen would go black. All of the system fans continued to run and the tape drive would eject its tape and the CD would respond to open the tray. Our only option would be to power off and start back up. We had not added any new hardware or installed any new programs. We did not have Windows Automatic updates turned on. There are no errors recorded in the BIOS Event Log; no information in the Memory.dmp file; and the only error recorded in the Event Logs is Event ID 1000 - "The reason for the unexpected shutdown is unknown". The lockups started to occur more frequently to a once or twice on a daily basis to the point where we would sometimes power off the server and start it back up but it would not even get to the POST screen until it had sat powered off for a few hours. We have replaced the power supplies and the power distribution board. We have tested the RAM and used CPU Tester Pro 4 to check the motherboard for errors and they both came up clean.
We formatted the drives and installed Windows Server 2003 but we continue to experience the same problems. Could a bad motherboard be creating the lockups or is there some other test we can run?
Thanks for your input.