If the monitor cannot display error messages during the POST,
the system may emit a series of beeps that identifies the problem
or that can help you identify a faulty component or assembly. The
following table lists the beep codes that may be generated during
the POST. Most beep codes indicate a fatal error that prevents
the system from completing the boot routine until the indicated
condition is corrected.
| Beep Code |
Error |
Probable Causes |
| 1-3 |
Monitor not
detected |
Disconnected or faulty
monitor |
| 1-1-3 |
NVRAM write/read
failure |
Defective system board |
| 1-1-4 |
BIOS checksum
failure |
Faulty BIOS or defective
system board |
| 1-2-1 |
Programmable
interval-timer failure |
Defective system board |
| 1-2-2 |
DMA
initialization failure |
Defective system board |
| 1-2-3 |
DMA page
register write/read failure |
Defective system board |
| 1-3-1 |
Main-memory
refresh verification failure |
Faulty or improperly seated
DIMM or defective system board |
| 1-3-2 |
No memory installed |
No memory installed or faulty or
improperly seated DIMM |
| 1-3-3 |
Chip or data
line failure in the first 64 KB of main memory |
Faulty or improperly seated
DIMM |
| 1-3-4 |
Odd/even logic
failure in the first 64 KB of main memory |
Faulty or improperly seated
DIMM |
| 1-4-1 |
Address line
failure in the first 64 KB of main memory |
Faulty or improperly seated
DIMM |
| 1-4-2 |
Parity failure
in the first 64 KB of main memory |
Faulty or improperly seated
DIMM |
| 2-1-1 through 2-4-4 |
Bit failure in
the first 64 KB of main memory |
Faulty or improperly seated
DIMM |
| 3-1-1 |
Slave
DMA-register failure |
Defective system board |
| 3-1-2 |
Master
DMA-register failure |
Defective system board |
| 3-1-3 |
Master
interrupt-mask register failure |
Defective system board |
| 3-1-4 |
Slave
interrupt-mask register failure |
Defective system board |
| 3-2-4 |
Keyboard-controller
test failure |
Faulty keyboard controller
(defective system board) |
| 3-3-4 |
Screen
initialization failure |
Faulty video subsystem
(defective system board) |
| 3-4-1 |
Screen-retrace
test failure |
Faulty video subsystem
(defective system board) |
| 3-4-2 |
Search for video
ROM failed |
Faulty video subsystem
(defective system board) |
| 4-2-1 |
No timer tick |
Defective system board |
| 4-2-2 |
Shutdown failure |
Defective system board |
| 4-2-3 |
Gate A20 failure |
Defective system board |
| 4-2-4 |
Unexpected
interrupt in protected mode |
Defective system board |
| 4-3-1 |
Memory failure
above address 0FFFFh |
Faulty or improperly seated
DIMM |
| 4-3-3 |
Timer-chip
counter 2 failure |
Defective system board |
| 4-3-4 |
Time-of-day
clock stopped |
Bad battery or defective
system board |
| 4-4-1 |
Serial-port test
failure |
Faulty I/O chip (defective
system board) |
| 4-4-2 |
Parallel-port
test failure |
Faulty I/O chip (defective
system board) |
| 4-4-3 |
Math coprocessor
failure |
Faulty microprocessor chip
or system board |
| 4-4-4 |
Cache test
failure |
Defective microprocessor or
system board |
