Dell OptiPlex 755 Quick Reference Guide - Page 72

Code 4-2-1 4-2-2 4-2-3 4-2-4 4-3-1 4-3-3 4-3-4 4-4-1 4-4-2 4-4-3 4-4-4 Cause No timer tick Shutdown failure Gate A20 failure Unexpected interrupt in protected mode Memory failure above address 0FFFFh Timer-chip counter 2 failure Time-of-day clock stopped Serial or parallel port test failure Failure to decompress code to shadowed memory Math-coprocessor test failure Cache test failure Resolving Software and Hardware Incompatibilities If a device is either not detected during the operating system setup or is detected but incorrectly configured, you can use the Hardware Troubleshooter to resolve the incompatibility. To start the Hardware Troubleshooter: Windows XP: 1 Click Start→ Help and Support. 2 Type hardware troubleshooter in the search field and press to start the search. 3 In the Fix a Problem section, click Hardware Troubleshooter. 4 In the Hardware Troubleshooter list, select the option that best describes the problem and click Next to follow the remaining troubleshooting steps. Windows Vista: 1 Click the Windows Vista start button , and click Help and Support. 2 Type hardware troubleshooter in the search field and press to start the search. 3 In the search results, select the option that best describes the problem and follow the remaining troubleshooting steps. 72 Quick Reference Guide