Troubleshooting Outline - Toyotomi TAD-T38J Service Manual

TROUBLESHOOTING OUTLINE

First, distinguish a location of malfunction.
(1) Is it a malfunction of a controlled part?
(2) Is it a malfunction of a controlling part?
(1) includes actual waking parts of
refrigeration cycle and motors.
(2) includes circuit board.
In the case of (1), distinguish further:
(3) Is it a problem of refrigeration cycle?
(4) Is it a problem of auxiliary devices?
(3) includes problems related to
refrigeration cycle such as capillary
blockage, coolant shortage and dirt on
a cooling unit.
(4) includes problems related to a fan
motor, compressor, louver motor, and
thermistor.
For problems of auxiliary devices, check
visually and/or by monitoring the status of
the devices.
• Motor is not rotating.
• Compressor is not running.
• Louver motor does not run.
First thing to do is to check the circuit board.
Is the circuit board trying to run?
Ex: Fan does not turn. It cannot be distinguished if it is a
malfunction of the fan, or of the circuit board.
blower on. Is there voltage at the fan motor terminal of the
circuit board? If so, the circuit board is normal. If not, the
circuit board is malfunctioning.
This is how to distinguish between:
(1) Is it a malfunction of a controlled part?
(2) Is it a malfunction of a controlling part?
Problems of a circuit board can be roughly divided into two groups.
1. Malfunction of microcomputer-controlled parts such as relays.
2. Malfunction of microcomputer
In either case, replace the circuit board.
For the problems such as dirt on a cooling unit, it is important to
perform a visual check first.
Part replacement is not necessary, and accurate analysis cannot
be performed with an unclean condition.
Check the refrigeration cycle, It is easier by comparing
temperatures at the evaporator inlet and outlet ports.
Problems that can be usually checked in the market place are:
• Coolant shortage
• Blockage of capillaries
In most cases, temperature of evaporator outlet port becomes high.
There is a possibility that problems are
caused by part malfunctions. It is
necessary to check parts of each part.
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Turn the air