Troubleshooting By Inferior Phenomena - Mitsubishi Electric PCA-A24GA Service Manual

10-3. TROUBLESHOOTING BY INFERIOR PHENOMENA

Phenomena
(1)LED2 on indoor controller board
is off.
Cause
• When LED1 on indoor controller board is also off.
1 Power supply of rated voltage is not supplied to out-
door unit.
2 Defective outdoor controller circuit board
3 Power supply of 208/230V is not supplied to indoor
unit.
4 Defective indoor power board
5 Defective indoor controller board
(For the separate indoor/outdoor unit power sup-
ply system)
1 Power supply of 208/230V AC is not supplied to
indoor unit.
2 The connectors of the optional replacement kit are
not used.
3 Defective indoor controller board
4 Defective indoor power board
19
Note: Refer to the manual of outdoor unit for the detail of remote controller.
1 Check the voltage of outdoor power
supply terminal block (L1,L2).
• When AC 208/230V is not detected,
check the power wiring to outdoor unit
and the breaker.
• When AC 208/230V is detected,
check 2 (below).
2 Check the voltage between outdoor
terminal block S1 and S2.
• When AC 208/230V is not detected.
—Check the fuse on outdoor controller
circuit board.
—Check the wiring connection.
• When AC 208/230V is detected,
check 3 (below).
3 Check the voltage between indoor terminal
block S1 and S2.
• When AC 208/230V is not detected,
check indoor/outdoor unit connecting
wire for mis-wiring.
• When AC 208/230V is detected,
check 4 (below).
4 Check voltage output from CN2S on indoor
power board (DC13.1V). Refer to 10-6-1.
• When no voltage is output, check the
wiring connection.
• When output voltage is between
DC12.5V and DC13.7V, check 5
(below).
5 Check the wiring connection between
indoor controller board and indoor power
board. Check the fuse on indoor controller
board. If no problems are found, indoor
controller board is defective.
1 Check the voltage of indoor power supply
terminal block (L1,L2).
• When AC208/230V is not detected,
check the power supply wiring.
• When AC208/230V is detected, check
2 (below).
2 Check that there is no problem in the
method of connecting the connectors.
• When there are problems in the method
of connecting the connectors, connect
the connector correctly referring to instal-
lation manual of an optional kit.
• When there is no problem in the
method of connecting the connectors,
check 3 (below).
3 Check voltage output from CNDK on
indoor controller board.
• When AC208/230V is not detected.
—Check the fuse on indoor controller board.
—Check the wiring connection between
indoor power supply terminal block and
CND on indoor controller board.
• When AC208/230V is detected, check
4 (below).
4 Check voltage output from CN2S on
indoor power board.
• When no voltage output, check the
wiring connection between CNDK on
indoor controller board and CNSK on
indoor power board.
If no problem are found, indoor power
board is defective.
• When DC12.5~13.7V is detected,
check the wiring connection between
CN2S on indoor power board and
CN2D on indoor power board.
If no problem are found, indoor con-
troller board is defective.
Countermeasure