32     IBM Desktop System HMM
Introduction
This chapter contains the check procedures used to 
diagnose the causes of product failures. The 
diagnostic information consists of:
Start:
   This is the starting point for any diagnostic 
action. Based on high-level symptoms, the check 
procedure directs you to more detailed procedures to 
help resolve machine failures.
Index of Symptoms, Messages, Error Codes, or 
Beeps: 
The tables for BIOS Error Messages, Codes, 
Beeps, and Error Symptoms list symptoms along with 
their probable causes, and direct you to the 
applicable check procedures to help resolve machine 
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 tables point 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 as instructed. If you do not remember the 
location of a specific part or test point, or an 
adjustment or removal procedure, see the chapter 
that contains that information. Always return to the 
check procedure after you do this. In some cases, 
you are referred to other check procedures to detect 
the cause of the failure.