Sharp SJ-21P-GY Service Manual page 13

(4) As a reference to determine the causes of trouble, malfunction and phenomena are described below.
Refer to the following when repairing.
1. Disconnection of Defrost heater
As off-cycle defrosting is performed, the defrosting time is extremely prolonged.
Each time defrosting is started, the freezer temperature rises and a portion of ice and stored foods are melted.
2. Melted Thermo. fuse or opened-circuit due to the defect of Defrost thermostat.
When the above mentioned trouble occurs in cooling operation, the timer motor does not run, defrosting will
not take place, and consequently freezing is caused.
In the above mentioned condition, when the timer shaft is turned by hand to defrost, the timer motor runs
during the operation time. However, the motor stops from the time when the contact is changed, and freezing
causes.
NOTE:
As Thermo. fuse assembly is intended to prevent dangers, do not use it under shorted condition even for a
short period.
3. When Defrost thermostat failure causes the circuit to remain closed.
The thermostat assembly connected with Thermo. fuse in the same way.
A portion of ice or stored foods are melted when Thermo. fuse is worked.
3. DEW PREVENTION
The hot pipe, namely D.P.-condenser, is arranged around the flange part of
cabinet and the C-partition plate, preventing dew from being generated on the
cabinet.
NOTE:
D.P.-condenser pipe may be felt hot if touched by hand while the compressor
is in operation.
If you are asked about this, please explain that the hot pipe serves to
prevent the dew generation.
4. INSPECTION OF INITIAL STARTING
(1) Inspection of cooling unit
1. Set the temperature control knob to "MAX" and check that the compressor starts to operate.
2. Depress the door switch to run the fan and check that cool air is blown out of the cold air outer of the
freezer and the refrigerator.
3. When the compressor does not work, check that the timer is not set to "defrost" position.
4. It takes about an hour and a half or 2 hours to put food in the refrigerator after starting operation.
NOTE:
After return the temperature control knob to "MED" position.
When the refrigerator is operated initially after installed,the compressor may vibrate excessively for 1 to 2
min. However, vibration becomes normal if it is continuously operated.
(2) Inspection of defrost device
Operate the refrigerator for 20 to 30 min. and then check the defrost device in the following procedures :
Allow 5 min. to restart the compressor since immediate starting after stopping will cause unsmooth operation.
1. Turn the timer shaft clockwise with a screw driver.
At this time, make certains the timer clinks and the compressor stops.
2. After more than 5 min., turn the shaft further to operate.
Make certain cooling operation is started again.
13
SJ-21P
SJ-D25P
Hot pipe
Fig. F-7