High Wall, Heat Pump Type
Service Manual
89
Toshiba
10-11.Inspection of the Main Parts
10-11-1.Inspection of the P.C. Board (Indoor Unit)
CAUTION
• When removing the front panel or the P.C. board, be sure to shut off the power supply breaker.
• When removing the P.C. board, hold the edge of the P.C. board and do not apply force to the parts.
• When connecting or disconnecting the connectors on the P.C. board, hold the whole housing. Do not pull at the lead
wire.
Inspection procedures
1) When a P.C. board is judged to be defective, check for disconnection, burning, or discoloration of the
copper foil pattern or this P.C. board.
NOTE
The P.C. board consists of the following 2 parts
• Main P.C. board part :
DC power supply circuit (5V, 12V, 15V), Indoor fan motor control circuit, CPU and peripheral circuits, buzzer,
and Driving circuit of louver.
• Indication unit of infrared ray receiving infrared ray receiving circuit, LED :
2) To check defect of the P.C. board, follow the procedure described below.
Check procedures
Table 10-11-1
No.
Procedure
Check points
Causes
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.
Check whether or not the fuse (F01) is
blown.
Impulse voltage was applied or the
indoor fan motor short-circuited.
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.
Check power supply voltage :
1. Between No. 1 and No. 3 of CN301
(AC 220–240V)
2.
Between
and
of
C03
(DC 310–340V)
3. Between
of IC122 and output side of
IC122 (DC 15V)
4. Between 12V and GND
5. Between 5V and GND
1. The terminal block or the crossover cable
is connected wrongly.
2. The capacitor (C01), line filter (L01),
resistor (R02), or the diode (DB01) is
defective.
3. IC101, IC122 and T101 are defective.
4. IC101, IC122 and T101 are defective.
5. IC101, IC122, IC121 and T101 are
defective.
3
Push [START/STOP] button once to start
the unit. (Do not set the mode to On-Timer
operation.)
Check power supply voltage :
1. Between CN03 and CN501 (DC 15–60V)
IC501 and IC502 are defective.
4
Shorten the restart delay timer and start unit. Check whether or not all indicators
(OPERATION, TIMER, PURE) are lit for 3
seconds and they return to normal 3
seconds later.
The indicators are defective or the
housing assembly (CN261) is defective.
5
Push [START/STOP] 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
(compressor) operates continuously in
the above condition.)
1. Check whether or not the compressor
operates.
2. Check whether or not the OPERATION
indicator flashes.
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.)
(CN602)
3. The heat exchanger sensor and the P.C.
board are defective.
(Refer to Table 10-6-1.)
4. The main P.C. board is defective.
+00A08-010_01EN_SVM_HighWallHeatPump.book Page 89 Wednesday, March 4, 2009 11:22 AM
