Dell OptiPlex N Service Manual (.pdf) - Page 36

Table 3-1. POST Beep Codes Beep Code Error Probable Causes 1-2 Video controller failure Defective system board 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 Defective system board failure 1-2-2 DMA initialization failure 1-2-3 1-3-1 1-3-2 1-3-3 DMA page register write/ read failure Main-memory refresh verifi- Faulty or improperly seated cation failure DIMM or defective system board No memory installed No memory installed or faulty or improperly seated DIMM Chip or data line failure in the Faulty or improperly seated first 64 KB of main memory DIMM 1-3-4 Odd/even logic failure in the first 64 KB of main memory 1-4-1 Address line failure in the first 64 KB of main memory 1-4-2 Parity failure in the first 64 KB of main memory 2-1-1 through 2-4-4 3-1-1 Bit failure in the first 64 KB of main memory Slave DMA-register failure Defective system board 3-1-2 Master DMA-register failure 3-1-3 Master interrupt-mask register failure 3-1-4 Slave interrupt-mask register failure 3-2 Dell OptiPlex N Systems Service Manual