The first step in determining the cause of the problem with the server is to gather whatever information you can from the service-call paperwork or the on-site personnel. Use the following general guidelines when you begin troubleshooting.
Events that occurred prior to the failure
Whether any hardware or software was modified or installed
Whether the server was recently installed or moved
How long the server exhibited symptoms
The duration or frequency of the problem
If possible, make one change at a time to isolate potential problems. In this way, you can maintain a controlled environment and reduce the scope of troubleshooting.