Mitsubishi Electric Mr. SLIM MSZ-FA25VA Technical Manual página 270

Resolución de averías
The unit does not operate with the remote controller.
Also, OPERATION INDICATOR lamp does not light up by pressing EMERGENCY OPERATION switch.
Check of indoor P.C. board and indoor fan motor
C
Turn OFF the power supply.
Remove indoor fan motor connector CN211 from indoor
power P.C. board and vane motor connector CN151
from the indoor electronic control P.C. board and turn
ON the power supply.
Does the unit operate with the remote controller?
Does OPERATION INDICATOR lamp light up by
pressing EMERGENCY OPERATION switch?
No
Turn OFF the power supply.
Check both "parts side" and "pattern
side" of the indoor terminal P.C.
board visually.
MSZ-HC25
Measure the resistance of indoor
fan motor.
Refer to 10-5.
Is the resistance normal?
Yes
Indoor terminal
P.C.board
Fuse (F11)
Varistor
(NR11)
270
Measure the resistance of indoor fan motor.
Refer to 10-5.
Yes
Measure the resistance of the vane motor coil.
Refer to 10-5.
No
Replace the fuse (F11) and
indoor fan motor. 3
Replace the fuse (F11). 3
Measure the resistance of cement
resistor R111 on the indoor power
P.C. board.
Indoor electronic
JPG (GND)
control P.C.board
CN10A
12VDC
5VDC
Indoor power P.C.board
R111
CN211
(MSZ-HC35)
CN211
(MSZ-HC25)
Short circuit:
Replace the indoor fan motor.
Short circuit:
Replace the vane motor and the indoor
electronic control P.C. board.
Replace the varistor(NR11) and fuse(F11). 3
Yes
No
Are the varistor (NR11) burnt
and the fuse (F11) blown?
Be sure to check both the fuse
and the varistor in any case.
No
Is the fuse (F11) blown only?
Yes
MSZ-HC35
Measure the resistance between
CN211 1 (+) and 3 (–) of indoor fan
motor connector. 1, 2
No
Is the resistance 1M
or more?
Yes
Is the resistance No
approx. 4 ?
Yes
Is the approx. 5VDC between 5V (+)
and JPG(GND) (–) of the indoor
electronic control P.C.board? Is there
approx. 9V to 13VDC between 12V (+)
and JPG (GND) (–) of the indoor
electronic control P.C. board.
No
Are connector CN10A on
Yes
the indoor electronic control
P.C. board or lead wires
disconnected?
No
Replace the indoor power / terminal P.C. board.
1. The fan motor connector's 1 lead wire is
red, whereas 3 is black.
2. Connect "+" of the tester to fan motor
1
connector's lead wire, and "–" to
lead wire, otherwise the resistance cannot
be measured properly.
3. Please replace the fuse after removing
the indoor terminal P.C. board from
the electrical box.
Replace the indoor power / terminal P.C. board
and the indoor fan motor.
Yes
Replace the indoor fan motor.
Connect the connector or repair
disconnection.
3