Daikin VKM50GAV1, Service Manual

Page: 86 / 107

Si71-812 Troubleshooting
Troubleshooting 77
2.21 Main Unit PC Board Assembly
Error Detection
Method Check microcomputer operation monitor.
Error Generating
Conditions When main unit PC board assembly does not operate.
When communication circuit errors.
Possible Causes Fuse (excess current)
Power transformer
Noise
Main unit PC board
Troubleshooting
Main unit PC board (A1P)
NO
NO
NO
YES
Does equipment
reset properly.
Is it flashing?
After checking
other possible
causes, replace
PC board assembly.
Is monitor indicator
Off?
YES
YES
Monitor indicator remains
On.
With remote controller
disconnected, check
microcomputer operation
monitor.
Turn off power, then
restart.
Noise may be causing erroneous
operation. If power reset does not
solve the problem, replace main unit
PC board.
There may be a malfunction in main
unit PC board fuse, main unit PC board
or power transformer.
Check fuse and transformer. If they are
normal, replace PC board.
Replace main unit PC board.
(HF013)
Caution
Be sure to turn off power switch before connect or disconnect connector,
or parts damage may be occurred.
HAP
(HL031)
(Microcomputor Operation Monitor)