72 Aspire XC600 Service GuideBeep CodesWhen no error message is displayed but the computer stops during POST, listen for beep codes.Undetermined ProblemsFollow the procedures below to isolate the failing FRU. Do not isolate non-defective FRU.1. Power off the computer.2. Visually check them for damage. If any problems are found, replace the FRU.3. Remove or disconnect all of the following devices:• Non-Acer devices• Printer, mouse, and other external devices• Hard disk drive• DIMM• CD/DVD-ROM drive• Expansion boards4. Power on the computer.5. Determine if the problem has been resolved.6. If the problem does not recur, reconnect the removed devices one at a time until you find the failed FRU.If the problem persists, replace the mainboard, and then LCD assembly (one at a time). Do not replace a non-defective FRU.Beep Status Possible CausesOne short beep. System ready System is OK.Continuous onelong beepMemory not installed ormemory error• Something is wrong with the memory installed• There is problem accessing the memory (i.e., mainboardproblem)One long beep,then two shortbeeps and repeatVGA not installed orVGA error• The mainboard can not access the video card for somereasons. Either the video card is not working, its memoryis not accessible, or its BIOS may be corrupt.• Something is wrong with the mainboard.One long beep,then one short beepBIOS failure BIOS damaged. Processor jump to boot block to executethe default procedure.Two short beeps. CMOS failure CMOS checksum errorNOTE • Verify that all attached devices are supported by the computer.• Verify that the power supply being used at the time of the failure is operating correctly. (See“Power System Check” on page 57)