Troubleshooting
N5500 Service Manual 41
Default Settings and
Troubleshooting
5.5.3 Switches/Knobs
Table 16 lists symptoms of problems and recommended actions to address problems
with the knob and front panel switches.
Table 16. Switches/Knob Problems
Symptom
Recommended Action
1. N5500 fails to power-
up when Power On/Off
switch is pressed.
1. Take steps as noted in paragraph 5.5.1.
2. N5500 powers-up,
but some or one of the
other switches respond.
1. Ensure Function switch PCB is plugged into Main PCB
assembly. If connection is good, change Function switch
PCB.
2. If problem persists, change Main PCB assembly.
3. When knob is rotated,
no highlight appears on
display screen, and/or
monitor does not
respond to knob presses.
1. Ensure encoder wire is plugged into Main PCB assembly.
If connection is good, change encoder.
2. If problem persists, replace Main PCB assembly.
5.5.4 Alarms/Audible Tones
Table 17 lists symptoms of problems and recommended actions to address problems
with the display and audible tones.
Table 17. Alarms/Audible Tones Problems
Symptom
Recommended Action
1. Alarm sounds for no
apparent reason
1. Moisture or spilt liquids can cause an alarm not to sound.
Allow the monitor to dry thoroughly before using
2. If the problem persists, replace Main PCB assembly.
2. Audible alarm does
not sound.
1. Check alarm silence status.
2. Verify alarm volume setting in Set-up menu.
3. Check 50 pi speaker connection. Ensure 50 pi speaker wire
is connected to rear communication PCB.
4. If problem persists, replace 50 pi speaker assembly.
5. Check the flat cable between main PCB and rear
communication PCB.
6. If problem persists, replace Main PCB assembly.
7. If problem persists, replace rear communication PCB.
3. N5500 responds to
switch press, but key
press tone fails to
sound.
1. Check Key Beep volume setting in Set-up menu.
2. Ensure 30 pi speaker wire is connected to rear
communication PCB.
3. If problem persists, replace 30 pi speaker assembly.
4. Check the flat cable between Main PCB and rear
communication PCB.
5. If problem persists, replace Main PCB assembly.
6. If problem persists, replace rear communication PCB.