63
4
Error Messages and Beep Codes
What This Chapter Contains
4.1
BIOS Front-panel Power LED Codes.................................................... 63
4.2
BIOS Error Messages ....................................................................... 63
4.3
Port 80h POST Codes ....................................................................... 64
4.1
BIOS Front-panel Power LED Codes
The front-panel power LED blinks off and on to display messages. For example, the
power LED is on when the system is powered on, and blinks off for 0.5 second when
processor initialization is complete. In addition, whenever a recoverable error occurs
during POST, the BIOS causes the front-panel power LED to blink an error message
describing the problem (see Table 30).
Table 30. Front-panel Power LED Blink Codes
Type
Pattern
Processor initialization complete
On when system powers up, then off for 0.5 second.
POST complete
On when system powers up, then off for 0.5 second.
BIOS update in progress
Off when update begins, then on for 0.5 second, then off for 0.5
second; pattern repeats until BIOS update is complete.
Video error
On-off (0.5 second each) two times, then 3.0 second pause (off)
between on-off blink pattern; repeat entire pattern (two on-off
blinks and pause) until system is powered off.
Memory error
On-off (0.5 second each) three times, then 3.0 second pause (off)
between on-off blink pattern; repeat entire pattern (three on-off
blinks and 3-second pause) until system is powered off.
Thermal warning
On-off (0.5 second each) four times, then 3.0 second pause (off)
between on-off blink pattern; repeat entire pattern (four on-off
blinks and 3-second pause) until 16
th
on blink, then end.
4.2
BIOS Error Messages
Table 31 lists the error messages and provides a brief description of each.
Table 31. BIOS Error Messages
Error Message
Explanation
CMOS Battery Low
The battery may be losing power. Replace the battery soon.
CMOS Checksum Bad
The CMOS checksum is incorrect. CMOS memory may have been
corrupted. Run Setup to reset values.
Memory Size Decreased
Memory size has decreased since the last boot. If no memory was
removed then memory may be bad.
No Boot Device Available
System did not find a device to boot.