R-252M (serv.man2) - Sharp Home Appliance Service Manual (repair manual). Page 10

R-252M   10

CARRY OUT 3D CHECKS.

Disconnect the leads from the terminals of the thermal cut-out. Then using an ohmmeter, make a
continuity test across the two terminals as described in the below.

CARRY OUT 4R CHECKS.

Temperature of "ON" condition  (closed circuit). ................................................... This is not resetable type
Temperature of "OFF" condition (open circuit). ....................................................................... Above 125˚C
Indication of ohmmeter (When room temperature is approx. 20˚C.) ....................................... Closed circuit

If incorrect readings are obtained, replace the thermal cut-out.

An open circuit thermal cut-out (OVEN) indicates that the food in the oven cavity may catch fire, this
may be due to over heating produced by improper setting of the cooking timer or failure of the control
panel.

CARRY OUT 3D CHECKS.
Isolate the switch to be tested and using an ohmmeter check between the terminals
as described in the following table.

COM; Common terminal,
NO;

Normally open terminal

NC;

Normally close terminal

If incorrect readings are obtained, replace the switch.

CARRY OUT 4R CHECKS.

Table: Terminal Connection of Switch

Plunger Operation

COM to NO

COM to NC

Released

Open circuit

Short circuit

Depressed

Short circuit

Open circuit

CARRY OUT 3D CHECKS.

1. If the fuse is blown, there could be a shorts or grounds in electrical parts or wire harness. Check them

and replace the defective parts or repair the wire harness.

2. If the fuse is blown when the door is opened, check the monitored latch switch and monitor switch.

If the fuse is blown by incorrect door switching replace the defective switch(es) and the  fuse F1.

CARRY OUT 4R CHECKS.