Service manual

26
No
(not clear)
Yes
Yes
Check of indoor fan motor
A
Check of remote controller and receiver P.C. board
B
When OPERATION INDICATOR lamp flashes 3-time. Indoor fan motor does not operate.
Disconnect lead wires from connector CN211 on the indoor electronic control P.C. board.
Measure resistance between lead wires No.1 and No.5 and then No.3 and No.5 (MSC-GE20/25/35VB)/
No.3 and No.4 and then No.1 and No.4 (MS-GE50VB, MSH-GE50VB).
Are lead wires connected?
Is soldered point of the connector
correctly soldered?
Is resistance 0 (short circuit) or (open circuit)?
Indoor unit operates by pressing the EMERGENCY OPERATION switch, but does not operate with the remote control-
ler.
Replace the batteries (Refer to 10-1.4.).
Is noise heard from radio?
Are there any fluorescent lights of
inverter or rapid-start type within
the range of 1 m?
Measure the voltage between receiver P.C. board connector CN302 No.3(-) and No.5(+) (MSC-GE20/
25/35VB)/CN301 No.1(+) and No.3(-) (MS-GE50VB, MSH-GE50VB) when the remote controller button is
pressed (Refer to 10-6.).
Is the voltage approximately 4 V DC?
Yes ( 0 or )
No
(others)
Yes
No
Yes
No
Is LCD display on the remote con-
troller visible?
Remove the batteries, then set them back
and press the RESET button. Check if the
unit operates with the remote controller.
Yes
Does the unit operate with the
remote controller?
Yes
OK
Yes
No
No
No (5 V or 0 V DC)
No
Resolder it.
Reconnect the lead wires.
Repair or replace the indoor fan motor.
Replace the remote controller.
Reinstall the unit away from lights.
Attach a filter on receiving part.
Replace the indoor electronic control P.C.
board.
Replace the power monitor, receiver P.C board or the receiver P.C. board.
Turn OFF the power supply.
Check connector CN211 visually.
Check if the remote controller is exclusive for this air conditioner.
Turn ON the power supply. Stop it if the unit operate.
Insert screwdriver into air outlet to rotate indoor fan
motor slowly for 1 revolution or over, and measure
voltage between No.2(+) and No.3(-) on CN121.
Replace the indoor electronic control P.C. board.
Does voltage repeat 0 V DC and 5 V DC?
Yes
No
10-5. TROUBLESHOOTING FLOW
Turn ON a radio to AM and press
OPERATE/STOP (ON/OFF) button on the
remote controller.
Press OPERATE/STOP (ON/OFF)
button on the remote controller.
OBH529A