Diagnostics; Problems And Solutions - NEC POWERMATE 8100 Series Service And Reference Manual

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.
Problem Symptom
No power Power lamp on computer status
panel does not light.
Power supply Any of the following conditions
malfunction could occur:
Front panel lamps out, diskette
and/or hard drives do not spin,
monitor blank, interface ports not
working, and keyboard lamp out
and/or cannot input from keyboard.
Operating system Intermittent beeping at power-on.
does not boot Computer beeps more than once
and is unable to complete boot-up.

Problems and Solutions

Solution
1. Check that the power cord is plugged
into the power socket on the computer.
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 riser board and between
the riser board and power switch.
3. Systematically eliminate possible
shorted PCBs by removing cables and
expansion boards.
4. Check the +5 and +12 power supply
voltages (see Section 4 "System Board").
Measure voltages with the system board
installed.
5. Replace the power switch assembly.
6. Replace the power supply.
7. Replace the system board.
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). See Section 4
for connector pin assignments and Section
10 for power supply specifications.
3. Replace the power supply.
1. Check system configuration (see
Section 2).
2. Check all jumper settings and verify that
drives are enabled (see Section 2).
3. Reseat DIMMs 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.
Troubleshooting 8-7