NEC POWERMATE ES Series, Service And Reference Manual

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7-6 Troubleshooting
Diagnostics
One beep indicates that the system has completed its POST test. If intermittent beeping occurs,
power off the system and try again. If the beeping persists, see the following table. The table
summarizes problems that may develop during system operation and lists (in sequential order)
suggested corrective actions.
Problems and Solutions
Problem Symptom Solution
No power Power lamp on front panel does
not light. 1. Check that the power cord is plugged into
the power socket on the system.
Check that the other end of the cord is
plugged into a live, properly grounded AC
power outlet.
2. Check cable connections between the
power supply and system board and
between the system board and power switch.
3. Systematically eliminate possible shorted
PCBs by removing cables and expansion
boards.
4. Check +5 and +12 power supply
voltages. Measure voltages with system
board installed.
5. Replace the LED board assembly.
6. Replace the power supply.
7. Replace the system board.
Power supply
malfunction Any of the following conditions
could occur:
Front panel lamps out, diskette
and/or hard drive does not spin,
monitor blank, interface ports not
working, and keyboard lamp out
and/or cannot input from keyboard.
1. Perform steps 1 through 4 listed in this
table under No Power.
2. Check power supply voltages. Voltages
should be measured with a load on them
(system board plugged in).
3. Replace the power supply.
Operating system
does not boot Intermittent beeping at power-on.
Computer beeps more than once
and is unable to complete boot-up. 1. Check system configuration (see
Section 2).
2. Check all jumper settings and verify that
drives are enabled (see Section 2 and
Section 4).
3. Reseat DIMMs, riser board, and option
boards in their connectors. Inspect system
board for foreign objects such as paper clips.
4. Remove option boards and reboot.
5. Replace system board.