Troubleshooting Method - Toshiba MMD-AP0726HP-UL Service Manual

9-2. Troubleshooting method

The remote controls (main remote control and central control remote control) and the interface P.C. board of
an outdoor unit are provided with an LCD display (remote control) or a 7-segment display (outdoor interface
P.C. board) to display operational status. Using this self-diagnosis feature, the trouble site / trouble part may
be identified in the event of a trouble by following the method described below.
The list below summarizes check codes detected by various devices. Analyze the check code according to
where it is displayed and work out the nature of the trouble in consultation with the list.
• When investigating a trouble on the basis of a display provided on the indoor remote control or TCC-LINK
central control remote control -
See the "TCC-LINK remote control or main remote control display" section of the list.
• When investigating a trouble on the basis of a display provided on an outdoor unit - See the "Outdoor 7-
segment display" section of the list.
• When investigating a trouble on the basis of a wireless remote control-controlled indoor unit - See the
"Indicator light block" section of the list.
List of check codes (indoor unit)
(Check code detected by indoor unit)
Check code
TCC-LINK
Outdoor 7-segment display
central control
or main remote
Sub-code
control
display
⎯
⎯
E03
⎯ ⎯
E04
E08 E08 Duplicated indoor address
⎯ ⎯
E10
⎯ ⎯
E11
⎯
⎯
E18
⎯ ⎯
F01
⎯ ⎯
F02
⎯
⎯
F03
⎯ ⎯
F10
⎯
⎯
F11
⎯ ⎯
F29
L03 ⎯ ⎯
⎯ ⎯
L07
⎯
L08 L08
⎯
⎯
L09
⎯ ⎯
L20
L30 L30 Detected indoor unit No.
⎯ ⎯
P01
P10 P10 Detected indoor unit No.
⎯
⎯
P12
⎯
⎯
P31
Display of receiving unit
Indicator light block
Typical trouble on site
Operation
Timer Ready
Flash
Indoor-remote control periodic
communication trouble
Indoor-outdoor periodic
communication trouble
Duplicated indoor address
UART communication trouble
Communication trouble
between Application control
P.C.Board and indoor unit
Check code in periodic
communication between indoor
header and follower unit
Indoor heat exchanger
ALT
temperature sensor (TCJ)
trouble
Indoor heat exchanger
ALT
temperature sensor (TC2)
trouble
Indoor heat exchanger
ALT
temperature sensor (TC1)
trouble
Ambient temperature sensor (TA)
ALT trouble
Discharge temperature sensor
ALT
(TF) trouble
P.C. Board or other indoor
SIM
trouble
Duplicated indoor group header
SIM
unit
Connection of group control cable
SIM
to stand-alone indoor unit
SIM Indoor group address not set
SIM Indoor capacity not set
SIM Duplicated central control address There is duplication in central control address setting.
Indoor external trouble
SIM
input (interlock)
ALT Indoor AC fan trouble
ALT Indoor overflow trouble
Indoor DC fan trouble
ALT
ALT Other indoor unit trouble
- 49 -
IPDU: Intelligent Power Drive Unit (Inverter P.C. board)
: Lighting, : Flashing, : Goes off
ALT.: Flashing is alternately when there are two flashing LED
SIM: Simultaneous flashing when there are two flashing LED
Description of check code
Communication from remote control or network adaptor has
been lost (so has central control communication).
Signals are not being received from outdoor unit.
Indoor unit detects address identical to its own.
Communication trouble between CDB(MCC-1643)
and FAN-IPDU(MCC-1610).
Communication check code between Application control
P.C.Board and indoor unit P.C. Board
Periodic communication between indoor header and follower units
cannot be maintained.
Heat exchanger temperature sensor (TCJ) has been open /
shortcircuited.
Heat exchanger temperature sensor (TC2) has been open /
shortcircuited.
Heat exchanger temperature sensor (TC1) has been open /
shortcircuited.
Ambient temperature sensor (TA) has been open / short-circuited.
Discharge temperature sensor (TF) has been open /
shortcircuited.
Indoor EEPROM is abnormal (some other trouble may be
detected).
There is more than one header unit in group.
There is at least one stand-alone indoor unit to which group control
cable is connected.
Address setting has not been performed for one or more indoor
units (also detected at outdoor unit end).
Capacity setting has not been performed for indoor unit.
Unit shutdown has been caused by external trouble
input (CN80).
Indoor AC fan trouble is detected (activation of fan motor
thermal relay).
Float switch has been activated.
Indoor DC fan trouble (e.g. overcurrent or lock-up) is
detected.
Follower unit cannot be operated due to header unit alarm
(E03 /L03 / L07 / L08).