If the monitor cannot display error messages during POST, the computer may emit a series of beeps that identifies the problem or that identifies a faulty component or assembly. The table below lists the beep codes that may be generated during POST.
| Beep Codes | Possible Cause | Corrective Action |
| 1-2 | Monitor not attached or on-board video controller defective | Connect the monitor. If problem persists, refer to Chapter 8, "Getting Help," in the Reference and Troubleshooting Guide for instructions on obtaining technical assistance. |
| 1-2-2-3 | BIOS ROM checksum error | Refer to Chapter 8, "Getting Help," in the Reference and Troubleshooting Guide for instructions on obtaining technical assistance. |
| 1-3-1-1 | DRAM refresh error | Reseat the DIMMs. |
| 1-3-1-3 | 8742 keyboard controller error | Reseat the keyboard connector. |
| 1-3-3-1 | Memory defective or not present | Reseat the DIMMs. |
| 1-3-4-1 | RAM failure on line xxx | Reseat the DIMMs. |
| 1-3-4-3 | RAM failure on data bits xxx of low byte on memory bus | Reseat the DIMMs. |
| 1-4-1-1 | RAM failure on data bits xxx of high byte on memory bus | Reseat the DIMMs. |