Daikin VKM50GAV1, Service Manual

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Si71-812 Troubleshooting
Troubleshooting 69
2.14 Data Transmission Error (between LCD Remote
Controller and Main Unit)
Remote
Controller LCD
Display Error Code
U5
Inspection
5
Unit No.
5
LED Indication Remote Controller 5 Main Unit 5
Error Detection
Method Microcomputer checks if data is transmitted properly between main unit and remote controller.
Error Generating
Conditions When data transmission is not performed correctly for a certain time period.
Possible Causes
„
Faulty connection of remote controller cable
„
Faulty remote controller cable
„
External factor (noise, etc.)
Troubleshooting
Note: Note 1:
1. Use tester to check continuity of remote controller cable.
„
Disconnect cable from main unit terminal board and remote controller terminal board.
Measure resistance between wires in cable. Resistance should be
∞
M
Ω
(infinity).
2. Use tester to check voltage at terminal board.
Check with power turned on.
„
With remote controller cable disconnected, voltage between P1 and P2 on terminal board
should be approx. 16 VDC. If measured value is not approx. 16 VDC, PC board assembly is
faulty.
„
Connect remote controller cable and disconnect remote controller. Voltage at the end of
remote controller cable should be approx. 16 VDC. If measured value is not 16 VDC, remote
controller cable is faulty.
„
Connect remote controller cable and remote controller. Voltage between P1 and P2 on
remote controller terminal should be approx. 16 VDC. If measured valued is not 16 VDC,
remote controller is faulty.
Check connection of
remote controller cable to
control PC board assembly
on terminal board.
Is
remote
controller cable
normal?
Note 1
YES
YES
Correct wiring.
Replace remote controller
cable.
Possibility of external factor
(instead of equipment error).
Is
connection
cable between
main unit and remote
controller
properly
wired?
NO
(HF008)
NO
Caution
Be sure to turn off power switch before connect or disconnect connector,
or parts damage may be occurred.
P2 P1
JC J2 J1 F2 F1 P2 P1
(HL032)
LCD
remote
controller
Remote
controller
Main unit PC board