Hitachi RAK-50NH5 Service Manual page 94

3. Only indoor fan does not operate (other is normal)
Can the fan be stopped by
remote control?
No
4. Air deflector does not move (others are normal)
Are pulse signals output at
microcomputer pin
swing is turned on in the fan mode?
Yes
Is a voltage over 15V or below 10V
being generated on the 12V line
5. All systems stop from several seconds to several minutes after operation is started (all indicators
are also off)
Set to the "Hi" fan mode.
The operation lamp lights once and goes out in 5-10 seconds.
Disconnect CN10 and set to the fan mode again.
The operation lamps lights once and goes out in 5-10 seconds.
Can the indoor fan be lightly turned by hand?
(Switch of main power before check)
Replace the indoor fan motor.
Yes
The microcomputer fan PWM
output (pin) is "Hi"
Perform final operation check.
No
- when auto
15 18
Yes
Perform final operation check.
Yes
No
Yes
Yes
No
Yes
Replace IC111
Yes
Check to see if shorting etc. has occurred
in the P.W.B pattern
No
Check to see if the indoor fan is touching
the chassis, etc. If it does repair
– 106 –
Replace the microcomputer.
Replace the indoor fan motor.
Replace the microcomputer.
Replace the microcomputer
Check IC711. If it is normal,
replace the air deflector motor.