Failure Diagnosis; Outline Of Control; When The Defrosting Failure Is Doubtful; Re-Setting Of Microcomputer At Power Failure - Sharp SJ-WS320TS Service Manual

SJ-WS320T-S

[ 8 ] FAILURE DIAGNOSIS

1. OUTLINE OF CONTROL

1) ON/OFF Control of Compressor
ON/OFF of the compressor will be controlled depend on the temperature detected by the R-thermistor and
F-thermistor. (Normal cooling control)
In case the surrounding temperature is high at the power supply input, the compressor will be ON at once and the
normal cooling control will start after several hours.
• During 6 minutes after the compressor stops, it will not start regardless of the detected temperature by R-thermistor
and F-thermistor.
2) Defrosting
Microcomputer calculates the appropriate timing of defrosting and defrosting is made automatically. Therefore
no manual operation by user is required. The cycle of defrosting varies depend on the usage condition of the
refrigerator. (Maximum time 50 hours, minimum time 40 minutes)
It is possible to perform defrosting forcedly by turning ON the power with the door of the refrigerating room opened.
3) Thermistor
Thermistors are installed in 4 places; in the refrigerator and freezer compartment, and on the Display PWB and close
to Evaporator. (R-thermistor, Fthermistor,Outside temp-thermistor, Def-thermistor)
R-thermistor and F-thermistor reads the temperature in the refrigerator and freezer compartment respectively and
controls ON/OFF of the compressor and OPEN/CLOSE of the electrical damper.
Def-thermistor detects the temperature around the evaporator and shows the progress of defrosting.
Outside temp-thermistor reads the surrounding temperature of refrigerator. It changes the operation mode by the
outside temperature.

2. WHEN THE DEFROSTING FAILURE IS DOUBTFUL

Execute the Self-Diagnosis Mode. (Refer to the Chapter "SELF-DIAGNOSIS MODE")
• In case the diagnosis result is " E03" (Def-thermistor system defect), follow up the flowchart of E03. (In case of any
abnormity in the Def-thermistor, defrosting will not be made for safety reasons.)
• In case the diagnosis result is " E07" (Defrost defect), follow up the flowchart of E07.
(This diagnosis result will be displayed when defrosting is made for 120 minutes, the maximum time length. In this
case, the defect of PWB itself and also the breakage of heater and heater circuit (melt down of current fuse and
temperature fuse) are considerable.)

3. RE-SETTING OF MICROCOMPUTER AT POWER FAILURE

• At the power failure for over about 1 second, the control of the microcomputer will be reset.
(Microcomputer might continue to operate for approximately 10 seconds maximum at power failure depending on the
load at the operation. When you need the difinite power off condition ,approximately 30 seconds is necessary.)
• When the power is re-supplied, the normal cooling will be resumed. (Defrosting is not maintained.)
• And the settings on the control panel will be restored to their condition before the power failure. (However "Express
Freezing" will not be restored.)
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