Hitachi RAF-25FX8 Mode D'emploi page 156

4. Check the control P.W.B. (power circuit)
Is 35V being output at pin ⑤
relative to 0V at pin ③ of
CN3?
Yes
Is 12V being output
at (+) relative to 0V at (-) of
C114?
Yes
Is DC5V being generated?
Yes
No
Check to see if the connection cables are
disconnected or reversed.
If normal, check the outdoor unit P.W.B.
No
Is ICP1 normal?
Normal if it is less than 1 .
Blown (open) if it is 1 or more.
Yes
(Normal)
Has the terminal board
thermal fuse blown (open)?
No
Replace Q111 and IC111.
No
Perform final operation check.
No
Yes
(Open)
– 174 –
Replace ICP1. Check if the air
deflector motor is shorted, and
IC111, Q111, C114, ZD121 are
defective.
If shorted / defective, ICP1 will be
open again.
Replace the terminal board.
Insert the connection cable
securely.
Replace IC121. Check if a short
occurs in the 5V line.
If the 5V line is shorted, ICP1 will
be open again.