4-9 
 
4.6.9 Power Supply Failures   
Symptoms   Possible Cause  Corrective Action 
Battery failure  Replace battery. 
Cable defective or 
poorly connected 
1. Check that the cable between battery 
interface board and power module is 
correctly connected. 
2. Check that cables and connectors are not 
damaged. 
Different battery 
voltages 
Power board failure  Replace the power board. 
Battery failure  Replace battery. 
Cable defective or 
poorly connected 
1. Check that the cable is correctly 
connected. 
2. Check that connecting cables and 
connectors are not damaged. 
Battery capacity is too 
low 
Power board failure  Replace the power board. 
Battery failure  Replace battery and recharge the replacement 
battery. If the replacement battery can be 
recharged, the original one fails. 
Cable defective or 
poorly connected 
1. Check that cable between battery interface 
board and power module is correctly 
connected. 
2. Check that cables and connectors are not 
damaged. 
Battery cannot be 
recharged 
Power board failure  Replace power board 
No +3.3 V output   
No +5.0 V output 
No +12 V output 
1. Power supply 
protected 
2. Power board failure 
1. Turn off the patient monitor then restart it. 
2. If the problem remains, disconnect the AC 
mains for 5 s and reconnect it, then restart 
the patient monitor. 
3. If the problem still remains, replace the 
power board.