R-90GCK (serv.man7). Test procedure - Sharp Home Appliance Service Manual (repair manual). Page 3

13

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

in the following table.

If incorrect readings are obtained, make the necessary switch adjustment or replace the switch.

3. CARRY OUT 4R CHECKS.

1. CARRY OUT 3D CHECKS.
2. Remove the back plate from the oven, referring to “BACK PLATE REMOVAL”.
3. If the high voltage fuse is blown, there could be a short in the high voltage rectifier or the magnetron.

Check them and replace the defective parts and the high voltage fuse.

4. CARRY OUT 4R CHECKS.

CAUTION: ONLY REPLACE HIGH VOLTAGE FUSE WITH THE CORRECT VALUE REPLACE-

MENT.

Table: Terminal Connection of Switch

Plunger Operation

COM to NO

COM to NC

Released

Open circuit

Short circuit

Depressed

Short circuit

Open circuit

COM; Common terminal,
NO;

Normally open terminal

NC;

Normally close terminal

1. CARRY OUT 3D CHECKS.
2. 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 obtained, replace the noise filter unit.

CARRY OUT 4R CHECKS.

1. CARRY OUT 3D CHECKS.
2. If the fuse 20A is blown, there is a shorts or grounds in electrical parts or wire harness Check then

and replace the defective parts or repaire the wire harness.

3. CARRY OUT 4R CHECKS.

1. CARRY OUT 3D CHECKS.
2. If the fuse F10A is blown when the door is opened, check the secondary interlock switch, relay RY2

and monitor switch.

3. If the fuse F10A is blown by incorrect door switching, replace the defective switch(s) and the fuse

F10A.

4. If the fuse F10A is blown, there is a shorts or grounds in electrical parts or wire harness.

Check them and replace the defective parts or repair the wire harness.

5. CARRY OUT 4R CHECKS.

CAUTION: ONLY REPLACE FUSE F10A WITH CORRECT VALUE REPLACEMENT.

FUSE

20A

N

L

LINE CROSS CAPACITOR   1.0

µ

/AC275V 

NOISE SUPPRESSION COIL 

LINE BYPASS 
CAPACITOR
0.0047

µ

/AC250V

LINE BYPASS
CAPACITOR
0.0047

µ

/AC250V

RESISTOR   
10M    1/2W

RESISTOR   680K    1/2W

WHT

RED

NOISE FILTER