54IntroductionThis chapter contains the check procedures used to diagnose the causes of product failures. The diagnostic informationconsists of:Start: This is the starting point for any diagnostic action. Based on high-level symptoms, the check procedure directs you tomore detailed procedures to help resolve machine failures.Index of Symptoms, Messages, Error Codes, or Beeps: The tables for BIOS Error Messages, Codes, Beeps, and ErrorSymptoms list symptoms along with their probable causes, and direct you to the applicable check procedures to help resolvemachine failures. These tables also list the field replaceable units (FRUs) most likely to cause a particular problem.Check Procedures: When the Start check procedure or the Index of Symptoms, Messages, Error Codes, or Beeps tablespoint you to a specific check procedure, proceed to that section. If there are any notes or instructions at the top of the page,read them before you begin with the procedure. Carefully read each step of the check procedure and perform the steps asinstructed. If you do not remember the location of a specific part or test point, or an adjustment or removal procedure, see thechapter that contains that information. Always return to the check procedure after you do this. In some cases, you arereferred to other check procedures to detect the cause of the failure.
