Daikin FTKS20CVMB, Service Manual, Page: 124 / 246

SiENBE04-401A Troubleshooting
Service Diagnosis 115
4.6 Signal Transmission Error (between Indoor and Outdoor
Unit)
Remote control
Display
U4
Method of
Malfunction
Detection
The data received from the outdoor unit in indoor unit-outdoor unit signal transmission is
checked whether it is normal.
Malfunction
Decision
Conditions
When the data sent from the outdoor unit cannot be received normally, or when the content of
the data is abnormal.
Supposed
Causes
„
Faulty outdoor unit PCB.
„ Faulty indoor unit PCB.
„ Indoor unit-outdoor unit signal transmission error due to wiring error.
„ Indoor unit-outdoor unit signal transmission error due to disturbed power supply waveform.
„ Indoor unit-outdoor unit signal transmission error due to breaking of wire in the connection
wires between the indoor and outdoor units (wire No. 2).
Troubleshooting
Check No.10
Refer to P.143
Check the o u tdoor u nit' s LED A.
Check the indoor u nit-o u tdoor u nit
connection wire s .
YE S
YE S
Correct the indoor u nit-o u tdoor
u nit connection wire s .
Di a gno s e the o u tdoor u nit.
Repl a ce the connection wire s
b etween the indoor a nd
o u tdoor u nit s .
Repl a ce indoor u nit control
PCB .
Loc a te the c aus e of the
di s t u r ba nce of the power su pply
w a veform, a nd correct it.
I s there a ny wiring error?
NO
(R2 8 40)
I s LED A fl as hing?
I s the volt a ge 0 V?
NO
Check No. 10
Check power su pply w a veform.
Check the volt a ge of the indoor
u nit-o u tdoor u nit connection wire s
b etween No. 1 a nd No. 2, a nd
b etween No 2 a nd No. 3 .
YE S
YE S
NO
I s there a ny di s t u r ba nce?
NO
Caution
Be su re to t u rn off power s witch b efore connect or di s connect connector,
or p a rt s d a m a ge m a y b e occ u rred.