Toshiba RAS-24UKX Service Manual page 41

Block level
Check Check
Block
code code
Indoor
P.C. board
The block is
unidentifiable
Cable
connection
Other parts
(including
compressor)
Table 9-4-1
Diagnosis function
Symptom
The indoor thermo sensor (TA) is
defective.
Disconnection or short-circuit
The indoor heat exchanger
sensor (TC) is defective.
Disconnection or short-circuit
The indoor fan motor or its circuit
is defective.
The part other than the above
parts on the indoor P.C. board is
defective.
EEPROM access error
IOL operation
The variation of TC, 5 minutes
after starting the compressor, is
2K or less.
The serial signals can not be
transmitted and received between
indoor and outdoor units.
• The crossover wire is
connected wrongly.
• The serial signal transmitting
circuit on the outdoor P.C. board
is defective.
• The serial signal receiving
circuit on the indoor P.C. board
is defective.
The operation command signals
are not transmitted from the
indoor unit to the outdoor unit.
The reply serial signal has been
transmitted when starting the
unit, but stops being transmitted
shortly after.
1. Compressor thermo operation
• Gas shortage
• Gas leak
2. Instantaneous power failure
The discharge temperature is
over 120°C.
The IOL operation is defective.
– 40 –
Unit
Condition
status
Operation The lamp on the
continues. indoor unit blinks
when error is
defected.
Operation The lamp on the
continues. indoor unit blinks
when error is
defected.
All off The lamp on the
indoor unit blinks
when error is
defected.
Operation The lamp on the
continues. indoor unit blinks
when error is
defected.
All off The lamp on the
indoor unit blinks
when error is
defected.
Operation The lamp on the
continues. indoor unit blinks
when error is
defected.
Operation The lamp on the
continues. indoor unit blinks
when error is
defected.
Operation The lamp on the
continues. indoor unit blinks
when error is
defected. And it
returns to the
normal condition
when recovering
from errors.
Operation The lamp on the
continues indoor unit blinks
when error is
defected. And it
returns to the
. normal condition
when recovering
from errors.
All off The lamp on the
indoor unit blinks
when error is
defected.
All off The lamp on the
indoor unit blinks
when error is
detected.
FILE NO. SVM-01010
Judgement and action
1. Check the indoor thermo sensor (TA).
2. Check the indoor P.C. board.
1. Check the indoor heat exchanger
sensor (TC).
2. Check the indoor P.C. board.
1. Check the connector circuit of the
indoor fan motor (CN10).
2. Check the indoor fan motor.
3. Check the indoor P.C. board.
1. Check the indoor P.C. board.
(EEPROM and peripheral circuits)
Overload operation of refrigerating cycle
1. Check whether or not the TC sensor
comes off.
2. Check whether or not it is possible to
operate the compressor and the
outdoor fan motor.
3. Check gas leak.
1. In the case of the outdoor unit not
operating at all;
• Check the crossover cable and
connect it properly.
• Check the outdoor P.C. board.
2. In the case of the outdoor unit operating
normally;
• Check whether or not both of serial
LED (Green) and serial LED (Orange)
is blinking.
If the serial LED (Green) is not
blinking, check the outdoor P.C. board.
If the serial LED (Orange) is not
blinking, check the indoor P.C. board.
If the operation command signals continue
to be transmitted between 2 and 3 of the
indoor terminal block, replace the outdoor
P.C. board.
1. Repeatedly turn the indoor unit on and
off with the interval of approx. 10 to 40
minutes. (The check code is not
indicated during operation.) And supply
gas. (Check gas leak.)
2. The indoor unit operates normally
during the check.
If the reply serial signal continues to be
transmitted between 2 and 3 of the
indoor terminal block, replace the
outdoor P.C. board.
If the signal stops between them,
replace the indoor P.C. board.
1. Check the heat exchanger sensor (TD).
2. Gas purging
When turning on the unit, the normal
phase (RST) is detected but T-R waveform
has not been detected for 120 seconds or
more.