Service Manual -
B-VMHxxAV-1
Troubleshooting 22
7.2 EL 01 (Indoor and Outdoor Unit Communication Error Diagnosis and Solution)
Description
: Indoor unit can not communicate with outdoor unit
Recommended parts to prepare:
• Signal wires
• Magnet ring
• Indoor PCB
• Outdoor PCB
Troubleshooting and repair:
XYE Communication:
No
Power off, then restart the unit 2
minutes later
Power off, then restart the unit 2
minutes later
Adopt shield cable/Shield cable
earthing.
Adopt shield cable/Shield cable
earthing.
No
Yes
Correct the connection.
Correct the connection.
No
Yes
Remove interference or
add magnet ring on power
wire
Remove interference or
add magnet ring on power
wire
Yes
Yes
Replace the signal wire.
Replace the signal wire.
Yes
Pull out and insert back.
Pull out and insert back.
No
No
Replace indoor main PCB, is the error
distinguished?
Replace indoor main PCB, is the error
distinguished?
Yes
Replace the outdoor main PCB.
Replace the outdoor main PCB.
No
Check whether there’s any
interference.
Such as too many lamps, power
transformers? Or the signal wire
is too long?
Check whether there’s any
interference.
Such as too many lamps, power
transformers? Or the signal wire
is too long?
Check whether the signal wire is
shield cable or whether the
shield cable is earthing?
Check whether the signal wire is
shield cable or whether the
shield cable is earthing?
Check whether the wire is
correct polarity? P to P, Q to Q, E
to E?
Check whether the wire is
correct polarity? P to P, Q to Q, E
to E?
Check whether the signal wire is
broken?
Check whether the signal wire is
broken?
Check whether the signal wires
insert on PCB well?
Check whether the signal wires
insert on PCB well?
Summary of Contents for Comfort-Aire Century A-VMH18SV-1
Page 30: ...Service Manual B VMHxxAV 1 ...
Page 37: ...Service Manual B VMHxxAV 1 Outdoor Unit 3 3 Panel Plate X430 Square grille ...
Page 38: ...Service Manual B VMHxxAV 1 Outdoor Unit 4 4 Panel Plate D30 Square grille ...
Page 39: ...Service Manual B VMHxxAV 1 Outdoor Unit 5 5 2 Service Place Minimim 4 Recommended 12 ...
Page 42: ...Service Manual B VMHxxAV 1 Outdoor Unit 8 8 A VMH18SV 1 A VMH24SV 1 ...
Page 45: ...Service Manual B VMHxxAV 1 ...
Page 103: ...Service Manual B VMHxxAV 1 Troubleshooting 15 ...