34 IBM Desktop System HMMIntroductionThis chapter contains the check procedures used todiagnose the causes of product failures. Thediagnostic information consists of:Start: This is the starting point for any diagnosticaction. Based on high-level symptoms, the checkprocedure directs you to more detailed procedures tohelp resolve machine failures.Index of Symptoms, Messages, Error Codes, orBeeps: The tables for BIOS Error Messages, Codes,Beeps, and Error Symptoms list symptoms along withtheir probable causes, and direct you to theapplicable check procedures to help resolve machinefailures. These tables also list the field replaceableunits (FRUs) most likely to cause a particularproblem.Check Procedures: When the Start checkprocedure or the Index of Symptoms, Messages,Error Codes, or Beeps tables point you to a specificcheck procedure, proceed to that section. If there areany notes or instructions at the top of the page, readthem before you begin with the procedure. Carefullyread each step of the check procedure and performthe steps as instructed. If you do not remember thelocation of a specific part or test point, or anadjustment or removal procedure, see the chapterthat contains that information. Always return to thecheck procedure after you do this. In some cases,you are referred to other check procedures to detectthe cause of the failure.
