Service manual
Troubleshooting Tables
4-6
2
Table 4-2 Power Supply and Battery
Symptom Possible Cause Corrective Action
AC indicator not lit. Power cord unplugged.
AC line voltage switch in wrong position.
One or both AC fuses are blown.
Power supply to CPU interface cables or key-
board cable not fully seated.
Bad power supply to CPU interface cable(s).
Bad keyboard circuit board.
Bad power supply.
Bad CPU assembly.
Plug in power cord.
Move to correct position.
Replace AC fuse(s).
Reseat cables.
Replace cable(s).
Replace keyboard assembly.
Replace power supply.
Replace CPU assembly.
Cardiograph doesn’t run on
battery, but runs on AC.
Battery connector is loose or defective.
Low battery or defective battery.
Software has stopped.
Battery fuse is blown.
Battery charger is defective.
Make sure battery connector is properly seated
and not defective.
Charge or replace battery.
Unplug from AC power. Remove battery. Wait
2 minutes. Reinstall battery and turn instru-
ment on.
Disconnect the battery and visually inspect the
battery fuse on the battery. Replace the battery,
if necessary.
Replace power supply assembly.
Cardiograph won’t power up
on AC or battery.
Power supply to CPU interface cables or key-
board cable not fully seated.
Power supply to CPU interface cable(s) is defec-
tive.
Software has stopped.
Keyboard circuit board is defective.
Power supply is defective.
CPU assembly is defective.
Reseat cables.
Replace the power supply to CPU interface
cable(s).
Unplug from AC power. Remove battery. Wait
2 minutes. Reinstall battery and turn instru-
ment on.
Replace the keyboard assembly.
Replace power supply assembly.
Replace CPU assembly.
Battery does not charge. AC line voltage switch in wrong position.
Defective power supply.
Defective battery.
Move to correct position
Remove battery. Using a voltmeter, measure
for approximately 6.8 Vdc across the battery
connector in the unit. Replace power supply, if
absent.
Replace battery.
Battery capacity too low. Battery is not fully charged.
AC line voltage switch in wrong position.
Defective or worn-out battery.
Fully charge battery.
Move to correct position.
Replace battery.
Cardiograph turns itself off
while plugged into AC
power.
AC line voltage switch in wrong position.
Power supply to CPU interface cables or key-
board cable not fully seated.
Defective power supply.
Move to correct position.
Reseat cables.
Replace power supply.