Faulty Outdoor Unit Pcb And Transmitting/Receiving Circuit - Daikin FTK25JV1NB Manual

Si-86.book Page 73 Friday, June 23, 2000 10:26 AM
SIE-86

5.16 Faulty Outdoor Unit PCB and Transmitting/Receiving Circuit

∗
Remote Controller
Display
3 3 3 3
Indoor unit LED
A
Display
Method of
1. The proper program operation of the microcomputer is checked by the program.
Malfunction
2. Signals transmitted from the outdoor unit to the indoor unit are received by the outdoor unit itself in
Detection
Malfunction
1. When the microcomputer program does not function properly.
Decision 2. When the signals transmitted from the outdoor unit to the indoor unit are received by the outdoor unit
Conditions
3. When the zero cross signal is not detected over 10 seconds.
Supposed Causes
Troubleshooting
Check No.13
Refer to P.82
Service Diagnosis
1 ∗ 2 ∗ 3 ∗ 4 ∗
indoor unit -outdoor unit signal transmission mode, and proper receiving of the signals by the indoor
unit is checked.
itself in indoor unit-outdoor unit signal transmission mode, but not properly.
Display disabled by faulty power supply.
Microcomputer program run-away due to an external factor.
∗Noise
∗Momentary voltage drop
∗Momentary power failure, etc.
Faulty outdoor unit PCB.
Check the power supply voltage.
NO
Is it at the rated voltage?
YES
Check the 5-VDC power supply of
the outdoor unit PCB.
NO
Is the voltage 5 ± 0.5 V?
YES
Turn the power off and back on
again.
Does
YES
the same LED indication
appear again?
Check the grounding.
NO
Check No. 13
Power supply waveform check
YES
Is there any disturbance?
NO
Turn off the power,
remove No. 2 of the terminal board,
and turn the power on again.
NO
Is it normal?
YES
Correct the power supply.
∗ Check the voltage at the terminals
marked with "5V" and "GND".
Replace the outdoor unit PCB.
NO
Is the grounding proper?
Provide the grounding.
YES
The malfunction may be caused by an
external factor, rather than defective
parts.
Locate the cause of the noise, etc.,
and correct the situation.
Locate the cause of the power supply
waveform disturbance, and take
necessary measures.
Replace the outdoor unit PCB.
Replace the indoor unit PCB.
Troubleshooting
(MF026)
73