Mitsubishi Electric MCFH-GA35VB Service Manual page 17

When OPERATION INDICATOR lamp flashes ON and OFF in every 0.5-second.
Outdoor unit does not operate.
How to check mis-wiring and serial signal error (when outdoor unit does not work)
E
Yes
Make them sure.
1. Turn OFF the power supply
(indoor/outdoor unit)
2. Short-circuit between indoor terminal block N and 3.
3. Turn ON the power supply
(indoor unit)
Is there 5V DC between J205 + –J101 - (MUCFH-GA35VB/GA50VB)/
J101 + –J401 - (MUCFH-GA60VB) on the deicer P.C. board?
As for outdoor unit MUCFH type, refer to the service manual OB381.
As for outdoor unit MXZ type, refer to the service manual OB319 REVISED EDITION-A.
All manuals and user guides at all-guides.com
Start
Is this mis-wiring, poor contact,
or disconnection of wire?
No
and disconnect indoor and outdoor connecting wire on indoor side.
and press once EMERGENCY OPERATION switch.
Is there 20V DC between both ends of
R132 on indoor electronic control P.C.
board ?
( By tester, the stylus is between 0 ~ 20V. )
Yes
•Turn OFF the power supply(indoor unit).
•Connect ON indoor and outdoor connecting wire.
Turn ON the power supply(outdoor unit).
Is there 230V AC between outdoor terminal
block L-N (TB1)?
Yes
Yes
Turn ON the power supply(indoor unit).
During EMERGENCY OPERATION,
is there 10V DC between both ends
of R601?
(By tester, the stylus is between 5 ~10V)
Yes
Replace the deicer P.C. board.
17
No
Replace the indoor electronic
control P.C. board.
Check the outdoor power supply,
No
power supply cord and
connection.
No
Replace the deicer P.C. board.
Make the wiring between CN730
No
on the deicer P.C. board and
outdoor terminal block correct.