Mitsubishi MXZ-4C36NAHZ - Page 111

111
Check method of multi controller circuit board
Normal
LED1 LED2
Fuse check
Check the fuse on multi controller circuit board
Did the fuse (F500) blow?
Replace multi controller circuit board (MULTI. B.)
and the defective fan motor.
See DC fan check.
Did the fuse (F1 and F2) blow? Check the SV1, SV2, SS and 21S4 and wiring.
7seg LED is lit?
(SW1: all off)
290 to 350 V DC?
• Check wiring.
• Replace multi controller circuit board.
• Check the breaker and main incoming power.
• Check power board.
• Check wiring.
Check the voltage from the power circuit
board
to CNDC (PNK) connector.
No
No
Yes
(lit)
No (No lit)
Yes
No
Multi controller circuit board check
Yes
(blow)
Yes (blow)
CNDC (PNK)
Power
circuit
board
3
1
1 3
CNDC
(PNK)
CNAC2
(RED)
Noise
Filter
Circuit
Conv.
Circuit
Multi controller
circuit board
290–350 V DC
208/230 V AC
±10%
208/230 VAC
TB1
±10%
CNAC
(RED)
F1
F2
F500
1
3
LI NI
L1 L2
Disconnect the FAN motor connector and
measure the resistance of connector pins.
Refer to “8-6. HOW TO CHECK THE PARTS”.
CN52C
(RED)
13 V DC
CN52
OCH573C