Troubleshooting Guide - Philips M3921A Service Manual

Troubleshooting Guide

50
Condition
4. The A1 turns on,
then shuts off and
sounds an alarm
and no error code is
displayed.
The following table lists recommended actions to address A3 power
problems.
Condition
1. The A3 fails to
power-up when the
ON/STANDBY
button is pressed.
Recommended Action
1. Press the alarm silence button to terminate the
audible alarm. Ensure that the external power supply
is connected and the green EXTERNAL POWER
indicator is lit. If the monitor operates successfully, the
battery could be discharged, or the battery fuse could
be blown.
2. Recharge the battery as directed in "Battery Charge"
on page 11. If the battery fails to hold a charge,
replace the battery.
3. Check fuse F301 located on the Main PCB, near the
battery cable connector. Replace the fuse if
necessary.
4. If problem persists, replace the main PCB.
Recommended Action
1. Ensure power cord is plugged into operational AC
outlet of appropriate voltage and frequency. Ensure
green BATTERY CHARGING/AC SOURCE indicator
is lit. If indicator is not lit, replace power supply
assembly.
2. Check fuses located on power supply assembly
above AC inlet receptacle. Replace fuses if
necessary.
3. Inside monitor, check main ribbon cable and ensure
that it is connected to main PCB and power supply
assembly.
4. Ensure that the keypad is plugged into Main PCB. If
the connection is good, replace the keypad.
5. If the problem persists, replace main PCB.
Chapter 5 - Troubleshooting