Maintenance and Troubleshooting 4-7Diagnosing and Solving ProblemsOne beep indicates that the computer has completed its power-on self-test. If intermittentbeeping occurs, power off the computer and try again. If the beeping persists, seeTable Section 4-3.Table Section 4-3 summarizes problems that may develop during computer operation andlists (in sequential order) suggested corrective actions.Table Section 4-3 Problems and SolutionsProblem Symptom SolutionNo power Power lamp on computer statuspanel will not light.1. Check that the power cord isplugged into the AC connector onthe computer.Check that the other end of thecord is plugged into a live properlygrounded AC power outlet.2. Check cable connectionsbetween power supply and systemboard.3. Systematically eliminate possiblyshorted PCBs by removing cablesand expansion boards.4. Check the +5 and +12 powersupply voltages (see Appendix A,Connector Pin Assignments).Measure voltages with the systemboard installed.5. Replace power supply.6. Replace system board.Power supplymalfunctionAny one or more of the followingconditions could occur:1. Perform steps 1 through 4 listedin this table under No Power.Front panel lamps out, disketteand/or hard drives do not spin,monitor blank, interface ports notworking, and keyboard lamp outand/or cannot input from keyboard.2. Check power supply voltages.Voltages should be measured with aload on them (system boardplugged in). See Appendix A forconnector pin assignments andAppendix B for the power supplyspecifications.4. Replace power supply.
