Troubleshooting For P.c. Board - Toshiba RAS-24UKX Service Manual

9-8. Troubleshooting for P.C. Board

9-8-1. How to check indoor P.C. board
<Cautions for handling P.C. board>
(1) When removing the front panel and the P.C. board,
be sure to turn off the power supply.
(2) When removing the P.C. board, hold the edge of
the P.C. board and do not apply force to the parts.
(3) When connecting or disconnecting the connectors
on the P.C. board, hold the housing. Do not pull at
lead wires.
<Inspection procedure>
No. Procedure
1 Turn off the power supply and
remove the P.C. board assembly
from electric parts base. Remove
the connecting cables from the
terminal block.
2 Remove the connector of the motor
and turn on the power supply. If
OPERATION lamp blinks (once per
second), it is not neccessary to
check steps (1 to 3) in the right
next column.
3 Press [START/STOP] button once
to start the unit. (Do not set the
mode to Fan Only or On-Timer
operation).
4 Shorten the line of the restart delay
timer and start unit.
(1) If the P.C. board is detective, check for disconnec-
tion, burn or discoloration of the copper foil pattern
of the P.C. board.
(2) The P.C. board consists of the following 2 parts:
a. Main P.C. board parts:
Power relay, indoor fan motor drive circuit and
control circuit, C.P.U. and peripheral circuits, buzzer
drive circuit and buzzer.
b. Infrared rays parts:
Infrared rays receiving circuit
Check the defects of the P.C. board with Table 9-8-1.
Table 9-8-1 Inspection procedure
Check points
Check whenther or not the fuse (F01)
is blown.
Check power supply voltage;
1. Between TP2 and TP3 of CN12
(220 – 240V AC)
2. Between + and – of CN02
(DC310 – 340V)
3. Between C04 and output side
of IC09 (DC15V)
4. Between 12V and GND
5. Between 5V and GND
Check power supply voltage;
1. Between connector of Q33 and
GND (for relay coil (DC12V))
2. Between 1 and 2 of terminal block
for connecting cable
Check whether or not all lamps
(OPERATION, TIMER, FAN ONLY,
ECONO. and AUTO) are indicated for
3 seconds and they return to normal
3 seconds later.
– 49 –
FILE NO. SVM-01010
Causes
Impluse voltage was applied or the
indoor fan motor short-circuited.
1. The terminal block or the
crossover cable is connected
wrongly.
2. The capacitor (C01 and C15),
line filter (L01), resistor (R01), or
the diode (DB01) is defective.
3. IC01, IC02 and T1 are defective.
4. IC01, IC02, and T1 are defective.
5. IC01, IC02, IC07 and T01 are
defective.
1. The wire of the relay coil (RY04)
comes down or the relay drive
(Q33) is defective.
2. CN27 or RY04 is connected
wrongly.
The lamps are defective or the
housing assembly (CN13) is
defective.