R-8000GK - Sharp Home Appliance Service Manual (repair manual). Page 14

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1. CARRY OUT 3D CHECKS.
2. A continuity check across the thermal cut-out terminals should indicate a closed circuit unless the

temperature of the thermal cut-out reaches approximately 150˚C. The thermal cut-out resets automatically
at approximately 130˚C. If thermal cut-out has opened under normal condition, replace the same item as in
the parts list.
An open thermal cut-out indicates overheating of the side heating element unit. Check for restricted air flow
to the side heat element  unit through the vent holes of the oven cavity, especially the heater duct left and
convection fan.

3. CARRY OUT 4R CHECKS.

CAUTION: IF THE THERMAL CUT-OUT INDICATES AN OPEN CIRCUIT AT ROOM TEMPERATURE,

REPLACE THERMAL CUT-OUT.

1. CARRY OUT 3D CHECKS.
2. Make sure the heating element is fully cooled and test as follows;

a. Disconnect wire leads from the heating element and measure the resistance with an ohmmeter. On the R

x 1 scale, the resistance between the heating element terminals should be approximately 37.2

Ω.

b. Disconnect wire leads from the heating element  and measure the insulation resistance with 500V -

100M

Ω insulation resistance meter. The insulation resistance between heating element terminal and

cavity should be more than 0.5M

Ω.

3. If the meter does not indicate above resistance, replace the top heating element.
4. CARRY OUT 4R CHECKS.

1. CARRY OUT 3D CHECKS.
2. Make sure the heating element is fully cooled and test as follows;

a. Disconnect wire leads from the heating element and measure the resistance with an ohmmeter. On the R x 1 scale,

the resistance between the heating element terminals should be approximately 55.7 

Ω.

b. Disconnect wire leads from the heating element  and measure the insulation resistance with 500V -

100M

Ω insulation resistance meter. The insulation resistance between heating element terminal and

cavity should be more than 0.5M

Ω.

3. If the meter does not indicate above resistance, replace the side heating element.
4. CARRY OUT 4R CHECKS.

1. CARRY OUT 3D CHECKS.
2. Remove the back plate from the oven, referring to “BACK PLATE REMOVAL”.
3. Disconnect connector-E from the control unit. Measure the resistance of the thermistor with an ohmmeter.

Connect the ohmmeter leads to Pin No’s E-5 and E-6.

Room Temperature

Resistance

68˚F(20˚C) - 86˚F(30˚C)

Approx. 360 k

Ω - 152 KΩ

4. If the meter does not indicate above resistance, replace the thermistor.

5. CARRY OUT 4R CHECKS.

1. CARRY OUT 3D CHECKS.
2. A continuity check across the temperature fuse terminals should indicate a closed circuit unless the temperature

of the  chassis support left reaches approximately 150˚C. An open temperature fuse indicates overheating of
the chassis support left. Check for restricted air flow to the chassis support left, especially the cooling fan.

3. CARRY OUT 4R CHECKS.

CAUTION: IF THE TEMPERATURE FUSE INDICATES AN OPEN CIRCUIT AT ROOM TEMPERATURE,

REPLACE TEMPERATURE FUSE.

1. CARRY OUT 3D CHECKS.
2. Disconnect input leads and check for short or open between the terminals using an ohmmeter.