Sharp DW-71-H Service Manual page 23

Trouble
5. The fan motor fails Both end voltage of fan
to run. motor
Fan motor
Fan motor drive circuit
Defrosting does not end.
Room temperature and
6. Although the
humidity
compressor and fan
motor run normally,
dehumidification is
impossible.
Filter
Refrigeration cycle
Frost on evaporator
7. Even when the FULL switch
water tank is fully
filled with water,
power is not turned
off and water flows
Float
over from the water
tank
The water tank has been
8. FULL WATER STOP
installed improperly.
acts even when the
tank is not full of FULL switch
water.
FULL circuit wiring
Room temperature
9. Abnormal frosting
Refrigeration cycle unit
on evaporator
Fan motor
Defrosting thermisto
Defrosting circuit
10. Defrosting does Defrosting thermistor
not end.
Defrosting circuit
Installation place
11. Noise (abnormal
Tightening parts
sound)
Fan
Piping pipe
FULL switch
12. Water leak
Dew pan
Float
Handling
Checking Troubleshooting and cause
• Voltage detected: Check the fan
motor.
• Voltage not detected: Check the
drive circuit.
Power is not supplied to winding.
Motor lock
Temperature fuse opened
• Connector contact failure
•Wiring material defect
•Power supply PWB ass'y failure
The fan motor stops and the
solenoid valve is turned on during
defrosting.
(Normally, defrosting ends within
5 to 15 minutes.)
Room temperature is lower than 1˚C
or humidity is lower than 50%.
Filter clogged
Coolant shortage or gas leak
Defrosting failure
Microswitch short-circuited
(Power is supplied continuously
even when the water tank is
removed.)
The float does not function normally.
Improper installation
Contact failure
FULL circuit wiring failure
Lower than 1˚C
Overcharge
Fan motor failure
Defrosting thermistor failure
Operation PWB ass'y failure
• Defrosting thermistor failure
• Improper insertion of defrosting
thermistor
• Connector contact failure
Power PWB ass'y failure
Floor inclines insignificantly.
Check tightness of screws.
Contact of fan with other parts
Contact of piping pipe with other
parts
FULL switch short-circuited
Condensate is not completely
received by the dew pan.
Float malfunction
The water tank was removed soon
after the FULL WATER STOP acted.
Repair or replace
Repair or replace
Replace.
Replace.
Replace.
Repair or replace.
Repair or replace.
Repair or replace.
Wait until defrosting ends.
Use within operating temperature
range 1 to 40˚C.
If relative humidity is less than 50%,
dehumidification rate reduces
remarkably.
Replace and clean the filter.
Replace the compressor and dryer
filter.
Check the defrosting circuit.
Replace.
Repair or replace.
Install correctly.
Replace.
Repair or replace.
Out of use range
Supply a new specified quantity of
coolant.
Replace.
Replace.
Repair or replace.
Replace.
Repair
Repair
Repair or replace.
Install on horizontal strong floor.
Retighten.
Prevent contact.
. Prevent contact.
Replace.
Check for deviation and deformation
of parts, check for inclination.
Correct.
Correct or replace.
Condensate on the cooler falls down
insignificantly. This phenomenon is
normal.
23
DW-71-H
Corrective action