Dell OptiPlex 755 Quick Reference Guide - Page 71

Code 1-3-1 through 2-4-4 4-3-1 Cause Memory not being properly identified or used Memory failure above address 0FFFFh If you experience any of the following beep code errors, see "Contacting Dell" in the User's Guide for instructions on obtaining technical assistance. Code 1-1-2 1-1-3 1-1-4 1-2-1 1-2-2 1-2-3 1-3 1-3-1 through 2-4-4 3-1-1 3-1-2 3-1-3 3-1-4 3-2-2 3-2-4 3-3-1 3-3-2 3-3-4 3-4-1 3-4-2 3-4-3 Cause Microprocessor register failure NVRAM read/write failure ROM BIOS checksum failure Programmable interval timer failure DMA initialization failure DMA page register read/write failure Video Memory Test failure Memory not being properly identified or used Slave DMA register failure Master DMA register failure Master interrupt mask register failure Slave interrupt mask register failure Interrupt vector loading failure Keyboard Controller Test failure NVRAM power loss Invalid NVRAM configuration Video Memory Test failure Screen initialization failure Screen retrace failure Search for video ROM failure Quick Reference Guide 71