Dell OptiPlex N Service Manual page 37

Table 3-1. POST Beep Codes (continued)
Beep Code Error
3-2-4 Keyboard-controller test
failure
3-3-4 Screen initialization failure
3-4-1 Screen-retrace test failure
3-4-2 Search for video ROM failure
4-2-1 No timer tick
4-2-2 Shutdown failure
4-2-3 Gate A20 failure
4-2-4 Unexpected interrupt in
protected mode
4-3-1 Memory failure above
address 0FFFFh
4-3-3 Timer-chip counter 2 failure
4-3-4 Time-of-day clock stopped
4-4-1 Serial-port test failure
4-4-2 Parallel-port test failure
4-4-3 Math coprocessor failure
4-4-4 Cache test failure
Probable Causes
Faulty keyboard controller
(defective system board)
Faulty video subsystem
(defective system board)
Defective system board
Faulty or improperly seated
DIMM
Defective system board
Bad battery or defective
system board
Faulty I/O chip (defective
system board)
Faulty microprocessor chip or
system board
Defective microprocessor or
system board
Beep Codes and Error Messages 3-3