R-671M - Sharp Home Appliance Service Manual (repair manual). Page 14

R-671M  -  14

CARRY OUT 3D CHECKS.

Before carrying out the following tests make sure the heating element is cool completely.

1. Resistance of heating element.

Disconnect the wire leads to the heating element to be tested.  Using ohmmeter with low resistance
range. Check the resistance across the terminals of the heating element as described in the
following table.

Table: Resistance of heating element

Parts name

Resistance

Grill heating element (top)

Approximately 88 

Ω

Bottom heating element

Approximately 150 

Ω

2. Insulation resistance.

Disconnect the wire leads to the heating element to be tested. Check the insulation resistance
between the element terminal and cavity using a 500V - 100M

Ω

 insulation tester.  The insulation

resistance should be more than 10 M

Ω

 in the cold start.

If the results of above test 1 and/or 2 are out of above specifications, the heating element is probably
faulty and should be replaced.

CARRY OUT 4R CHECKS.

CARRY OUT 3D CHECKS.

Disconnect the leads from the terminals of noise filter.
Using an ohmmeter, check between the terminals as
described in the following table.

Between N and L

Approx. 680 k

Ω

Between terminal N and WHITE

Short circuit

Between terminal L and RED

Short circuit

If incorrect readings are absorbed, replace the noise filter unit.

CARRY OUT 4R CHECKS.

CARRY OUT 3D CHECKS

If the fuse F8A is blown when the door is opened, check the primary latch switch, monitor switch and
monitor resistor.

If the fuse F8A is blown by incorrect door switching replace the defective switch(es) and the  fuse F8A.

CARRY OUT 4R CHECKS.

CARRY OUT 3D CHECKS.

Disconnect the leads from the motor. Using an ohmmeter, check the resistance between the two
terminals as described in the table below.

Table: Resistance of Motor

Motors

Resistance

Fan motor

Approximately 300 

Ω

Turntable motor

Approximately 14.9 k

Ω

If incorrect readings are obtained, replace the motor.

CARRY OUT 4R CHECKS.

LINE BYPASS
CAPACITOR
4700p/250V

LINE BYPASS
CAPACITOR
4700p/250V

NOISE SUPPRESSION COIL

RESISTOR 680K/0.5W

10M/0.5W

LINE CROSS CAPACITOR
0.22

µ

/250V

FUSE 15A

FUSE F8A

NOISE 
FILTER

L

N

WHT

RED