Sharp R-8000G Service Manual page 21

PROCEDURE
LETTER
temperature of the thermal cut-out reaches approximately 338˚F(170˚C). The thermal cut-out resets
automatically at approximately 311˚F(155˚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 top heating element unit. Check for restricted air flow
to the top heat element unit through the vent holes of the oven cavity, especially the heater duct upper and
convection fan.
6. Reconnect all leads removed from components during testing.
7. Reinstall the outer case (cabinet).
8. Reconnect the power supply cord after the outer case is installed.
9. Run the oven and check all functions.
CAUTION: IF THE THERMAL CUT-OUT INDICATES AN OPEN CIRCUIT AT ROOM TEMPERATURE, RE-
L THERMAL CUT-OUT (SIDE HEATER) TEST
1. Disconnect the power supply cord.
2. Remove the outer case cabinet, referring to "OUTER CASE CABINET REMOVAL".
3. Open the door and block it open.
4. Discharge high voltage capacitor.
5. A continuity check across the thermal cut-out terminals should indicate a closed circuit unless the
temperature of the thermal cut-out reaches approximately 302˚F(150˚C). The thermal cut-out resets
automatically at approximately 266˚F(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.
6. Reconnect all leads removed from components during testing.
7. Reinstall the outer case (cabinet).
8. Reconnect the power supply cord after the outer case is installed.
9. Run the oven and check all functions.
CAUTION: IF THE THERMAL CUT-OUT INDICATES AN OPEN CIRCUIT AT ROOM TEMPERATURE, RE-
M TOP HEATING ELEMENT TEST
1. Disconnect the power supply cord.
2. Remove the outer case cabinet, referring to "OUTER CASE CABINET REMOVAL".
3. Open the door and block it open.
4. Discharge high voltage capacitor.
5. 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 27.8Ω.
b. Disconnect wire leads from the heating element and measure the insulation resistance with 500V -
100MΩ insulation resistance meter. The insulation resistance between heating element terminal and
cavity should be more than 0.5MΩ.
6. If the meter does not indicate above resistance, replace the top heating element.
7. Reconnect all leads removed from components during testing.
8. Reinstall the outer case (cabinet).
9. Reconnect the power supply cord after the outer case is installed.
10. Run the oven and check all functions.
N SIDE HEATING ELEMENT TEST
1. Disconnect the power supply cord.
2. Remove the outer case cabinet, referring to "OUTER CASE CABINET REMOVAL".
3. Open the door and block it open.
4. Discharge high voltage capacitor.
5. 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 35 Ω.
TEST PROCEDURES
PLACE THERMAL CUT-OUT.
PLACE THERMAL CUT-OUT.
COMPONENT TEST
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R-8000G