Chapter 2. Power On Self Tests (POST)/Problem Isolation
Chapter 2.1 Introduction
This section provides a list of assemblies checked by the Power On Self Test
(POST) and a brief description of the types of error codes.
The section also
contains preliminary steps to problem isolation of an error condition and a
problem isolation flowchart for quick reference.
Chapter 2.2 Power On Self Test (POST)
A series of diagnostic tests automatically run on every COMPAQ Personal
Computer system when the system is turned on.
These tests are called the
Power On Self Test (POST).
POST checks the following assemblies to ensure that the computer system is
functioning properly:
o
Keyboard
o
Power Supply
o
System Board
o
Video Display Controller Board
o
Fixed Disk Drive Controller Board
o
Diskette/Printer Controller Board
o
Asynchronous Communications/Clock Board
o
System Board
o
Memory
POST also detects the type(s) of mass storage device(s) installed in the
computer.
When the computer is turned on, POST automatically starts and runs.
If POST
finds an error in the system, error codes (in the form of beeps) are heard or
error codes (numbers) are visible on the monitor.
See Chapter 5, "Error
Messages and Codes," for an explanation of error codes.
Chapter 2.3 Preliminary Steps to Problem Isolation
If you encounter an error condition, complete the following preliminary steps
before starting problem isolation.
1.
Place the ON/OFF switch in the OFF position.
2.
Disconnect the signal cables of any peripheral devices (printers, modems,
and so on) from the computer.
3.
Remove the upper access panel and board slots access cover (see Chapter 7,
"Removal and Replacement Procedures.")
When the upper access panel is removed, the system LED, located on the
