SiBE04-101
Troubleshooting
Service Diagnosis
95
4.8
Faulty Indoor Unit PCB
Remote Controller
Display
∗
Indoor unit LED
Display
Method of
Malfunction
Detection
The proper program operation of the microcomputer is checked by the program.
Malfunction
Decision
Conditions
When the microcomputer program does not function properly.
Supposed Causes
Microcomputer program is in abnormal condition due to an external factor.
∗
Noise.
∗
Momentary voltage drop.
∗
Momentary power failure, etc.
Faulty indoor unit PCB.
Troubleshooting
Turn on the power again.
Check the grounding. (earth)
YES
YES
Replace the indoor unit PCB(2).
Replace the indoor unit PCB(1).
Provide proper grounding.
The malfunction may be
caused by an external factor,
rather than defective parts.
Locate the cause of the noise,
etc., and correct the situation.
Operating normally?
Is the grounding proper?
(R1055)
NO
YES
NO
Are 5V and 12V
outputted at PCB (1) ?
NO
Caution
Be sure to turn off power switch before connect or disconnect connector,
or parts damage may be occurred.
SiBE04-101.book Page 95 Monday, October 15, 2001 3:08 PM