Mitsubishi SRK13YJV-S Technical Manual & Parts List page 48

(b) Indoor unit fan motor check procedure
This is a diagnostic procedure for determining if the indoor unit fan motor or the indoor PCB is broken down.
1) Indoor PCB output check
a) Turn off the power.
b) Remove the front panel, then disconnect the fan motor lead wire connector.
c) Turn on the power. If the unit operates when the ON/OFF button is pressed, if trouble is detected after the voltages in
the following figure are output for approximately 30 seconds, it means that the indoor PCB is normal and the fan
motor is broken down.
If the voltages in the following figure are not output at connector pins No. ① , ④ and ⑤ , the indoor indoor PCB
has failed and the fan motor is normal.
DC several V
(4~6 V)
CNU
2) DC Fan motor resistance check
Measuring Point
① – ③ (Red – Black)
④ – ③ (White – Black)
(10) How to make sure of wireless remote controller
(1)
Is remote
controller normal?
YES
Again pushing
operating switch
Operating the unit?
NO
Does unit ON/OFF
button operates?
Operating the unit.
NO
Control problem on
main unit
(–)
GND
DC15V
⑥ ⑤ ④ ③
⑥ ⑤ ④ ③
FM
I
Resistance when Normal
25 M Ω or higher
30 k Ω or higher
NO
Remote controller
defects
YES
Abnormality is not
found.
YES
DC 308~336V
Indoor PCB
② ①
② ①
Notes (1) Remove the fan motor and measure it without power connected to it.
Notes (2) If the measured value is below the value when the motor is normal, it means
that the fan motor is faulty.
Replace the display.
Is the unit
operable with remote
controller?
NO
Defective remote
controller
Note (1) Check method of remote controller
(a) Press the reset switch of the remote controller.
(b) If all LCD are displayed after one (1) display, it is basically normal.
46
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YES
Normal