SiUS091601EA
Troubleshooting for Outdoor Unit
Part 6 Service Diagnosis
180
7.16 Signal Transmission Error on Outdoor Unit PCB
Error Code
U7
Method of Error
Detection
Communication error between microcomputer mounted on the main PCB and PM1.
Error Decision
Conditions
The abnormality is determined when the data sent from the PM1 cannot be received for 9
seconds.
The error counter is reset when the data from the PM1 can be successfully received.
Supposed
Causes
Defective outdoor unit PCB
Troubleshooting
(R21
8
0
8
)
Caution
YES
N
O
T
u
rn off the po
w
er
. Then, t
u
rn on
the po
w
er to restart the system.
Error again?
The ca
u
se can
b
e an
external factor other than
the malf
u
nction.
O
b
ser
v
e the operating
condition in long term.
Be s
u
re to t
u
rn off the po
w
er s
w
itch
b
efore connecting or disconnecting
connectors, or parts may
b
e damaged.
Replace the o
u
tdoor
u
nit
PCB (main PCB).
Summary of Contents for FDMQ12RVJU
Page 18: ...SiUS091601EA 13 Part 2 Specifications 1 Specifications 14 Part 2 Specifications ...
Page 198: ...Check SiUS091601EA 193 Part 6 Service Diagnosis 18 24 class R24538 1 2 3 4 Multimeter ...
Page 201: ...SiUS091601EA Check Part 6 Service Diagnosis 196 18 24 class R24539 DC DC W V U ...
Page 229: ...SiUS091601EA Piping Diagrams Part 8 Appendix 224 RXL15QMVJU RXL18UMVJU 3D100007 3D123368 ...
Page 230: ...Piping Diagrams SiUS091601EA 225 Part 8 Appendix RXL24UMVJU 3D107985A ...
