Hitachi RAS-18YH4 - Page 77

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2. Indoor fan does not operate (others are normal)
Can the fan be stopped by remote
control?
The microcomputer fan PWM
Replace the microcomputer
.
Replace the fan motor .
Replace the microcomputer .
Perform final operation check.
Are pulse signals output at
microcomputer pins 15 - 18 when
auto swing is turned on in the fan
mode?
Replace the microcomputer.
Is a voltage over 15 or below 10V
being generated on the 12V line?
No
No
No
No
Perform final operation check.
output (at pin
24 ) is 1 - 5V.
Check IC711. If it is normal,
replace the air deflector motor.
Replace IC111.
3. Air deflector does not move (others are normal)
YesYes
Yes
Yes