Dell OptiPlex GX520 - Manual (Page 209)

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.
2. Run the Dell Diagnostics to identify a more serious cause.
3. Contact Dell for technical assistance.
A failure has occurred.
This pattern also displays when you enter
system setup and may not indicate a
problem.
l Ensure that the cables are properly connected to the system board from the hard
drive, CD drive, and DVD drive.
l Check the computer message that appears on your monitor screen.
l If the problem persists, contact Dell .
After POST is complete, all four diagnostic
lights turn green briefly before turning off
to indicate normal operating condition. None.
Light Pattern Problem Description Suggested Resolution
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
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
3-2-2 Interrupt vector loading failure
3-2-4 Keyboard Controller test failure
3-3-1 NVRAM power loss
3-3-2 Invalid NVRAM configuration
3-3-4 Video Memory test failure
3-4-1 Screen initialization failure
3-4-2 Screen retrace failure
3-4-3 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 or parallel port test failure
4-4-2 Failure to decompress code to shadowed memory
4-4-3 Math-coprocessor test failure
4-4-4 Cache test failure