Midea CTBU-09HWFN1-M Service Manual page 99

For 36K-48K:
Malfunction
conditions
Possible causes
E1 displayed
E1 displayed
Communication malfunction between indoor
Communication malfunction between indoor
and outdoor units
and outdoor units
Power off, then restart the unit 2
Power off, then restart the unit 2
minutes later. Does a problem still
minutes later. Does a problem still
exist?
exist?
Yes
Is there any interference such
Is there any interference such
as too many lamps, power
as too many lamps, power
transformers? Or is the signal
transformers? Or is the signal
wire too long?
wire too long?
No
Is the signal wire a shield cable
Is the signal wire a shield cable
and is the shield cable a
and is the shield cable a
earthing?
earthing?
Yes
Is the signal wire is broken?
Is the signal wire is broken?
No
Are the signal wires properly
Are the signal wires properly
inserted on PCB?
inserted on PCB?
Yes
Replace the indoor main PCB, is the
Replace the indoor main PCB, is the
error resolved?
error resolved?
No
Replace the outdoor Main PCB.
Replace the outdoor Main PCB.
Indoor unit does not receive feedback from outdoor unit for 60
seconds OR outdoor unit does not receive feedback from indoor unit
for 120 seconds.
● Wiring mistakes
● Faulty indoor or outdoor PCB
Yes
No
Yes
No
96
Remove interference or
Remove interference or
add magnet ring on power
add magnet ring on power
wire
wire
Adopt shield cable/shield
Adopt shield cable/shield
cable earthing
cable earthing
Replace the signal wire
Replace the signal wire
Pull out and insert back
Pull out and insert back