How To Check Simply The Main Parts - Toshiba RAS-107SKV-E3 Service Manual

11-6. How to Check Simply the Main Parts

11-6-1. How to check the P.C. board (Indoor unit)
(1) Operating precautions
1) When removing the front panel or the P.C.
board, be sure to shut off the power supply
breaker.
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 connec-
tors on the P.C. board, hold the whole housing.
Do not pull at the lead wire.
(3) Checking procedure.
No. Procedure
1 Turn off the power supply breaker
and remove the P.C. board
assembly from electronic parts
base. Remove the connecting
cables from the terminal block.
2 Remove the connector of the
motor and turn on the power
supply breaker. If OPERATION
indicator flashes (once per
second), it is not necessary to
check steps (1 to 3) in the right
next column.
3 Push [ ] button once
to start the unit. (Do not set the
mode to On-Timer operation.)
4 Shorten the restart delay timer
and start unit.
5 Push [ ] button once
to start the unit,
• Shorten the restart delay timer.
• Set the operation mode to
COOL.
• Set the fan speed level to
AUTO.
• Set the preset temperature
much lower than the room
temperature. (The unit (com-
pressor) operates continuously
in the above condition.)
(2) Inspection procedures
1) When a P.C. board is judged to be defective,
2) The P.C. board consists of the following 2 parts
Table 11-6-1
Check points
Check whether or not the fuse (F01)
is blown.
Check power supply voltage :
1. Between No. 1 and No. 3 of CN01
(AC 220–240V)
2. Between and of C27
(DC 310–340V)
3. Between 12V and GND
4. Between 5V and GND
Check power supply voltage :
1. Between CN51 and
No. 1 of CN01 (DC 15–60V)
Check whether or not all indicators
(OPERATION and TIMER) are lit
for 3 seconds and they return to
normal 3 seconds later.
1. Check whether or not the com-
pressor operates.
2. Check whether or not the
OPERATION indicator flashes.
– 68 –
FILE NO. SVM-10017
check for disconnection, burning, or discolora-
tion of the copper foil pattern or this P.C. board.
a. Main P.C. board part:
DC power supply circuit (5 V, 12 V, 15 V),
Indoor fan motor control circuit, CPU and
peripheral circuits, buzzer, and Driving circuit
of louver.
b. Indication unit of infrared ray receiving
Infrared ray receiving circuit, LED:
To check defect of the P.C. board, follow the
procedure described below.
Impulse 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,C02 or C27),
line filter (L01), resistor (R64),
or the diode (DB01) is defective.
3. T01 and IC01 are defective.
4. T01 and IC02 are defective.
IC51 and IC52 are defective.
The indicators are defective or the
housing assembly (CN20) is defective.
1. The temperature of the indoor heat
exchanger is extremely low.
2. The connection of the heat
exchanger sensor is loose.
(The connector is disconnected.)
(CN62)
3. The heat exchanger sensor and the
P .C. board are defective.
(Refer to Table 11-4-1.)
4. The main P.C. board is defective.
Causes