Dell Precision T7400 (Late 2007) - Manual (Page 115)

Troubleshooting Tools 115
– Ensure that the main power cable and front panel cable are securely
connected to the system board (see "System Board Components" on
page 27).
Beep Codes
Your computer might emit a series of beeps during start-up if the monitor
cannot display errors or problems. This series of beeps, called a beep code,
identifies a problem. One possible beep code (code 1-3-1) consists of one
beep, a burst of three beeps, and then one beep. This beep code tells you that
the computer encountered a memory problem.
If your computer beeps during start-up:
1 Write down the beep code on the "Diagnostics Checklist" on page 286.
2 Run the Dell Diagnostics to identify a more serious cause (see "Dell
Diagnostics" on page 123).
3 Contact Dell for technical assistance (see "Contacting Dell" on page 287).
Code Cause
1-1-2 Microprocessor register failure
1-1-3 NVRAM read/write failure
1-1-4 ROM BIOS checksum failure
1-2-1 Programmable interval timer failure
1-2-2 DMA initialization failure
1-2-3 DMA page register read/write failure
1-3 Video Memory Test failure
1-3-1 through 2-4-
4
Memory not being properly identified or used
1-3-2 Memory problem
3-1-1 Slave DMA register failure
3-1-2 Master DMA register failure
3-1-3 Master interrupt mask register failure
3-1-4 Slave interrupt mask register failure