IBM 6648 - Manual (Page 47)

Diagnostics, test and recovery information
The following tools are available to help identify and resolve hardware-related
problems.
v Power-On Self-Test (POST)
– POST Beep Codes
– Error Code Format
v IBM PC Enhanced Diagnostics
v Recovery utility
– Full recovery
– Partial recovery
v Repair utility
Power-On Self-Test (POST)
Each time you power-on the system, it performs a series of tests that check
the operation of the system and some options. This series of tests is called the
Power-On Self-Test, or POST. POST does the following operations.
v Checks some basic system-board operations
v Checks the memory operation
v Starts the video operation
v Verifies that the diskette drive is working
v Verifies that the hard disk drive is working
If the POST finishes without detecting any problems, a single beep sounds
and the first screen of the operating system or application program appears.
Note: Type 6568/6569/6648/6649 computers default to come up quiet (no
beep and no memory count and checkpoint code display) when no
errors are detected by POST. To enable beep and memory count and
checkpoint code display when a successful POST occurs, do the
following:
1.
Select Start Options in the Configuration/Setup Utility program
(see “Setup Utility program” on page 41).
2. Set Power-On Self-Test to Enhanced.
If the POST detects a problem, an error message appears on the screen. A
single problem can cause several error messages to appear. When you correct
the cause of the first error message, the other error messages probably will not
appear on the screen the next time you turn on the system.
POST beep codes
The Power-On Self-Test generates a beeping sound to indicate successful
completion of POST or to indicate that the tests detect an error.
Chapter 2. Types 6568/6569/6648/6649 33