Mitsubishi Heavy Industries SRK25GZ-L1 Handbook page 913

(ii) Parts layout on the indoor unit printed circuit board
Model selector
Control selection
switch
Outdoor unit number
address switch
Indoor unit number
address switch
● Replacement procedure of indoor unit micrcomputer printed circuit board
Microcomputer printed circuit board can replaced with following procedure.
1) Confirm the parts numbers. (Refer to the following parts layout rdrawing for the location of pats number.)
Parts No.
PJA505A073ZA FDTS, FDR, FDUM, FDE, FDK, FDFL, FDFU
PJA505A074ZA FDT, FDTW
● Model select switch (SW6)
Model
22 28 36 45
Switch
SW OFF ON OFF ON
6-1
SW OFF OFF ON ON
6-2
SW OFF OFF OFF OFF
6-3
SW OFF OFF OFF OFF
6-4
(iii) Check method when the error code is displayed
Remote controller or Indication board: Inspection LED, error code
Indoor unit PCB: Red LED ( inspcetion display), Green LED ( CPU. normal display )
Outdoor unit PCB: Red LED ( inspcetion display), Green LED ( CPU. normal display )
(iv) Check procedure depending on indication lamps (For the indoor unit)
The next page error diagnosis is applicable to cases where only 1 unit is installed in a network unless stated otherwise but the
check method is same even if there are multiple units on the network. Except the network occupation state due to out of control
indoor unit CPU, the error display indicates the state of respective units. Check each unit specified by the error display as
explained on next page.
Transformer
(
primary side
Return air
HA connector
thermistor
Heat exchanger
Limit switch input
thermistor
for the auto swing
Model
56 71 90 112 140
OFF ON OFF ON OFF
OFF OFF ON ON OFF
ON ON ON ON OFF
OFF OFF OFF OFF ON
● Function of jumper wires
J1
Transformer
secondary side
J2
Power supply
)
connector for PCB
J3
J4
J5
(2)
J6
(2)
J6
J7
J8
Note (1) "None" means that jumper wire is not provided
Indoor and outdoor
unit transmission
● Function of DIP switches
Switch
ON Input Reverse Invalid
SW
5-1
Signal
Rus stop
OFF
ON Heating temp. shift + 3°C
SW
5-2
OFF Normal
ON Test run of condensate pump motor
SW
5-3
OFF Normal
FDC-HKX
Name Function
Setting of 4 position angle of louver
With
(1)
None Setting of 4 position angle of louver
4 position louver control : Valid
With
(1) 4 position louver control : Invalid
None
Heating thermostat OFF - Intermittent
With
operation
(1)
None Heating thermostat OFF - Stop
Filter sign : Valid
With
(1)
None Filter sign : Invalid
Normal operation operable
With
(1) Operation permission prohibited
None
Expansion valve aperture - Fixed at
With
current aperture.
Expansion valve aperture - Fixed at
(1)
None
new aperture.
Automatic detection of expansion valve
With
aperture opening (only for J71, 90)
Expansion valve aperture - Fixed at
(1)
None
new aperture.(except J71, 90)
Expansion valve aperture - Normal
With
(1)
None Impossibility
With Spare
Spare
(1)
None
on the PCB or the connection is cut.
(2) Only FDT series has the following control.
Function Reference page
837
832
835
911