20
Parts layout on the indoor unit PCB
Models: FDTN (P), FDEN (P) series
Model: FDKN (P) series
(3)
Error diagnosis procedures at the indoor unit side
To diagnose the error, measure the voltage (AC, DC), resistance, etc. at each connector around the circuit board of indoor unit
based on the inspection display or the operation state of unit (no operation of compressor or blower, no switching of 4-way valve,
etc.). If any defective parts are discovered, replace with the assembly of parts as shown below.
(a)
Single-unit replacement parts for circuit board of indoor unit.
(Peripheral electric parts for circuit board.)
Indoor unit printed circuit board, thermistor (return, heat exchanger), operating switches, limit switches,
transformers, fuses.
Note (1) Use normal inspection methods to determine the condition of strong electrical circuits and fro-
zen cycle parts.
(b)
Replacement procedure of indoor unit microcomputer printed circuit board
Microcomputer printed circuit board can be replaced with following procedure.
(i)
Confirm the parts numbers. (Refer to the following parts layout drawing for the location of parts number.)
Parts number
PJA505A069
PHA505A007
Model
FDKN(P)258, 308
FDT, FDR, FDU, FDFL
Parts number
PHA505A008
PJA505A092Z
Model
FDTN(P), FDEN(P)
FDKN(P)208
Transformer, primary side
Power
supply
Transformer, secondary side
Power supply connector
for PCB
( )
External input /
output function
For test mode selection
(Shortcircuit : Test mode)
Thermistor
(Return air, heat exchanger)
Receiving unit
Backup switch
Indiction lamps
( )
SW4
SW3
SW5
1
CNL
CNN
CNH
CNQ
CNE
SW3
SW4
SW5
CNV
CNT
52X6
52X5
52X4
52X7
52X1
52X3
52X2
9 7 6 3 4 8 13
11 10
Thermistor
(Return air, heat exchanger)
For test mode selection
(Shortcircuit : Test mode)
External input /
output function
Receiving unit
( )
Backup switch
Indiction lamps
Transformer, primary side
Transformer, secondary side
Power supply connector
for PCB
( )
Power
supply
SW5
SW3
SW4
SW2
SW2 (Only case of FDTN)
(Optional : For auto lift panel)
