When Led1 On Indoor Controller Board Is Also Off; When Led1 On Indoor Controller Board Is Lit - Mitsubishi Electric Mr.Slim PKA Series Service Manual

9-4. TROUBLESHOOTING OF PROBLEMS
Phenomena
(1)LED2 on indoor controller board
is off.
OCH758
Note: Refer to the outdoor unit's service manual for the detail of remote controller.
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 220–240 V is not supplied to indoor
unit.
4 Defective indoor controller board
(For the separate indoor/outdoor unit power sup-
ply system)
1 Power supply of 220–240 V AC is not supplied to
indoor unit.
2 The connectors of the optional replacement kit are
not used.
3 Defective indoor controller board

• When LED1 on indoor controller board is lit.

1 Mis-setting of refrigerant address for outdoor unit
(There is no unit corresponding to refrigerant
address "0".)
1 Check the voltage of outdoor power
supply terminal block (L, N) or (L
• When 220–240 V AC is not detected,
check the power wiring to outdoor unit
and the breaker.
• When 220–240 V AC is detected, check
2 (below).
2 Check the voltage between outdoor
terminal block S1 and S2.
• When 220–240 V AC is not detected,
—check the fuse on outdoor controller
circuit board.
—check the wiring connection.
• When 220–240 V AC is detected, check
3 (below).
3 Check the voltage between indoor termi-
nal block S1 and S2.
• When 220–240 V AC is not detected,
check indoor/outdoor unit connecting
wire for miswiring.
• When 220–240 V AC is detected,
check 4 (below).
4 Check the fuse on indoor controller
board.
Check the wiring connection.
If no problem is found, indoor controller
board is defective.
1 Check the voltage of indoor power supply
terminal block (L,N).
• When 220–240 V AC is not detected,
check the power supply wiring.
• When 220–240 V AC 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 refer-
ring to installation manual of an optional
kit.
• When there is no problem in the meth-
od of connecting the connectors,
check 3 (below).
3 Check the fuse on indoor controller
board.
Check the wiring connection.
If no problem is found, indoor controller
board is defective.
1 Check again the setting of refrigerant
address for outdoor unit.
Set the refrigerant address to "0".
(For grouping control system under
which 2 or more outdoor units are
connected, set one of the units to "0".)
Set refrigerant address using SW1 (3-6)
on outdoor controller circuit board.
22
Countermeasure
, N).
3