Dell OptiPlex 745c (Early 2007) - Manual (Page 115)

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 (see Dell Diagnostics ).
3. Contact Dell for technical assistance (see Contacting Dell ).
Memory modules are detected, but a
memory configuration or compatibility error
exists. l Ensure that no special memory module/memory connector placement requirements
exist (see Memory ).
l Verify that the memory modules that you are installing are compatible with your
computer (see Memory ).
l If the problem persists, contact Dell (see Contacting Dell ).
A failure has occurred.
This pattern also displays when you enter
system setup (see
Entering 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 (see Contacting 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