Compaq.com - Compaq Presario Maintenance and Service Guide - 4900, 5000, & 5100 Series
United States December 9, 2002
Maintenance and Service Guide
Compaq Presario 4900, 5000, & 5100 Series Computers
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Product Description
Troubleshooting
Illustrated Parts Catalog
Removal & Replacement
Jumper & Switch Information
Specifications
Clearing CMOS
Power-On
Self Test
(POST)
Configuration
Diagnostic error
codes
Troubleshooting
without
diagnostics
l
TROUBLESHOOTING
Power-On Self Test (POST)
POST
is a series of diagnostic tests that run automatically when the system is turned on. After the
computer is turned on,
POST
checks the following assemblies to ensure that the computer system is
properly functioning:
■
Keyboard
■
System board
■
Memory modules
■
Video memory
■
Diskette drives
■
Hard drive
■
Power supply
POST
also detects the type of mass storage devices installed in the computer.
If
POST
finds an error in the system, an error condition is indicated by an audible and/or visual
message. The table below gives explanations of the error codes and a recommended course of action.
NOTE:
An external speaker must be installed into the speaker output connector to
hear audible beeps during
POST
.
Click a link below to find the probable cause and recommended action for a given error message.
Diskette Drive A or B Error
Keyboard Controller Error
System BIOS Shadowed
Extended RAM failed at
offset
nnn
Keyboard Error
System Cache Error
Failing Bits
nnn
Operating System Not
Found
System CMOS Checksum Bad
Fixed Disk 0 or 1 Failure
Parity Check 1
System RAM Failed at Offset,
nnn
Fixed Disk Controller Failure
Parity Check 2
System Timer Error
Incorrect Drive A Type
Real Time Clock Error
UMB Upper Limit Segment
Address
nnn
Invalid NVRAM Media Type
System Battery is Dead
Video BIOS Shadowed
POST Messages
Error message
Probable Cause
Recommended Action
Diskette Drive A or
B Error
Drive A: or B: is present, but fails the
BIOS POST diskette tests
1. Run Setup.
2. Replace the signal cables.
3. Replace the drive.
Extended RAM
failed at offset
nnn
Extended memory not working or not
configured properly
1. Replace the memory modules.
2. Replace the system board.
Failing Bits
nnn
nnn
is a map of the bits at the RAM
address which failed the memory test
1. Run Setup.
2. Replace the system board.
Fixed Disk 0 or 1
Failure
Hard drive is not working or not
configured properly
1. Run Setup.
2. Replace the signal cable.
3. Replace the hard drive.
Fixed Disk
Controller Failure
Hard drive is not working or not
configured properly
1. Run Setup.
2. Replace the system board.
Incorrect Drive A
Type
Type of diskette in drive A: not
correctly identified
1. Run Setup.
2. Replace the diskette drive.
Invalid NVRAM
Media Type
Problem with NVRAM (CMOS) access
Replace the system board.
Keyboard Controller
Error
Keyboard, I/O keyboard controller (on
system board), or mouse error
1. Replace the keyboard.
2. Replace the mouse.
3. Replace the system board.
Keyboard Error
Keyboard, I/O keyboard controller (on
system board), or mouse error
1. Replace the keyboard.
2. Replace the mouse.
3. Replace the system board.
Operating System
Not Found
Operating system cannot be located on
either drive A: or C:
Run Setup.
Parity Check 1
Parity error found in the system bus
1. Run Setup.
2. Replace the memory modules.
3. Replace the system board.
Parity Check 2
Parity error found in the I/O bus
1. Run Setup.
2. Replace the ISA board (modem).
Real Time Clock
Error
Real-time clock fails BIOS test
Replace the system board.
System Battery is
Dead
RTC battery is dead
1. Replace the RTC battery.
2. Run Setup.
System BIOS
Shadowed
System BIOS copied to Shadow RAM
Status message. No action required.
System Cache Error
RAM cache failed the BIOS test
Run Setup.
System CMOS
Checksum Bad
CMOS is corrupted or modified
incorrectly
Run Setup.
System RAM Failed
at Offset,
nnn
System RAM failed
Replace memory modules.
System Timer Error
DMA, timers, etc.
Replace the system board.
UMB Upper Limit
Segment Address
nnn
Displays the address
nnn
of the upper
limit of Upper Memory Blocks,
indicating released segments of the
BIOS
Status message. No action required.
Video BIOS
Shadowed
Video BIOS successfully copied to
shadow RAM
Status message. No action required.
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