Toshiba RAS-18YKH-E Service Manual page 21

9-2. Primary Judgment of Trouble
Sources
9-2-1. Role of Indoor Unit Control
The indoor unit controller receives the operation
commands from the remote control and assumes
the following functions.
• Measurement of the draft air temperature of the
indoor heat exchanger by using the thermo
sensor (TA).
• Louver motor control
• Control of the indoor fan motor operation
• Control of the LED display
• Sends the operation signal to the outdoor micro-
computer.
A OPERATION display flashing (1 Hz)
B OPERATION display flashing (5 Hz)
C OPERATION display flashing (5 Hz)
D OPERATION display flashing (5 Hz)
E OPERATION display flashing (5 Hz)
F OPERATION and TIMER display flashing (5 Hz)
G OPERATION, TIMER and PRE-DEF. display
flashing (5 Hz)
H OPERATION, TIMER and PRE-DEF. display
flashing (5 Hz)
(1) Judgement from defective operation or abnormal operation
Symptom
No reaction on Turn off the power once, turn it on
remote control again and try to operate the remote
operation control again.
The outdoor fan The compressor operates.
does not rotate
The compressor does not operate.
Block display
Check
9-2-2. Display of Abnormalities and
Judgement of the Abnormal Spots
The indoor unit of this machine observes the opera-
tion condition of the air conditioner and displays the
contents of the self-diagnosis as block displays on
the display panel of the indoor unit.
Table 9-2-1
Power failure (when power is ON)
Thermo sensor (TA) short/break
Heat exchanger sensor (TC) short/break
Indoor fan lock, abnormality of indoor fan
Indoor P.C. board failure
Wrong wiring of connecting cable
• Gas shortage, other refrigerant cycle trouble
• Heat exchanger sensor open/break/short
• Overload relay or thermostat for compressor
trouble
Cycle abnormal
Table 9-2-2
Remote control is
not possible.
Remote control is
possible.
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Block display
Primary judgement
The indoor part (including the
remote control) is defective.
OK.
The outdoor part is defective.
(outdoor fan motor)
The inside part is defective.