Maintenance and Troubleshooting 4-7Table Section 4-2 System Error MessagesMessage DescriptionTable Section 4-3 ISA NMI Error MessagesMessage DescriptionMemory Parity Error at xxxxx Memory failed. If the memory location can be determined, it isdisplayed as xxxxx. If not, the message is Memory ParityError ????.Memory Parity Error at xxxxx An expansion card failed. If the address can be determined, it isdisplayed as xxxxx. If not, the message is I/O Card Parity Error????.DMA Bus Time-out A device has driven the signal for more than 7.8 microseconds.Diagnosing and Solving ProblemsOne beep indicates that the computer has completed its power-on self-test. If intermittent beepingoccurs, power off the computer and try again. If the beeping persists, seeTable Section 4-4. The table summarizes problems that may develop during computer operationand lists (in sequential order) suggested corrective actions.Table Section 4-4 Problems and SolutionsProblem Symptom SolutionNo power Power lamp on computer statuspanel will not light.1. Check that the power cord is pluggedinto the AC connector on the computer.Check that the other end of the cord isplugged into a live properly grounded ACpower outlet.2. Check cable connections betweenpower supply and system board.3. Systematically eliminate possiblyshorted PCBs by removing cables andexpansion boards.4. Check the +5 and +12 power supplyvoltages (see Appendix A, Connector PinAssignments). Measure voltages with thesystem board installed.5. Replace power supply.6. Replace system board.
