Service manual

2. TROUBLESHOOTING
2.2 Service Manual BSM-4100
Power-Related Problems
Problem Possible Cause/Criteria Action
No AC power input. Check the AC power input.
One or both AC inlet fuses is blown. Remove the cause of the blown fuse, then
replace the fuse.
Faulty connection between CN105 on the
MAIN board and power unit.
Check the connection of MAIN board and
power unit.
Faulty connection between CN103 on the
MAIN board and power SW board.
Check the connection.
Faulty power supply unit. Replace the power supply unit.
No beep sound and
AC power lamp does
not light in AC power
operation.
Faulty power SW board. Replace the power SW board.
The battery is discharged. Charge the battery before use.
The battery is damaged. Replace the battery.
No beep sound and
the battery power
lamp does not light in
DC power operation.
Faulty cable connection between CN021 on the
MAIN board and battery receptacle terminals.
Check the connection.
The battery is near the end of its life (about 1
year).
Replace the battery with a new one.
Poor contact between the battery and its contact
points in the battery compartment.
Clean the contact points between the
battery and its compartment terminals.
To clear this “memory effect”, fully
discharge the battery and then fully charge
it a few times.
DC power operation
time is shorter than
expected.
The battery has had “memory effect” in which
its charge capacity is decreased by frequent
incomplete discharging and charging.
Replace the battery with a new one.
Faulty power SW board. Replace the power SW board.
Power switch is not
operational.
Faulty MAIN board. Replace the MAIN board.