R-4G75M (serv.man7). Complete - Sharp Home Appliance Service Manual (repair manual). Page 25

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transformer.

5. Remove the two (2) screws and one (1) washer holding

the transformer to base plate.

6. Remove the transformer.
7. Now, the power transformer is free.

1. Door does  not close firmly.
2. Door hinge, support or latch hook is damaged.
3. The door gasket or seal is damaged.
4. The door is bent or warped.
5. There are defective parts in the door interlock system.
6. There are defective  parts in the microwave generating

and transmission assembly.

7. There is visible damage to the oven.

Do not operate the oven:
1. Without the RF gasket (Magnetron).
2. If the wave guide or oven cavity are not intact.
3. If the door is not closed.
4. If the outer case (cabinet) is not fitted.

1. CARRY OUT 3D CHECKS.
2. Make sure that a definite "click" can be heard when the

microwave oven door is unlatched. (Hold the door in a
closed position with one hand, then push the door open
button with the other, this causes the latch heads to rise,
it is then possible to hear a "click" as the door switches
operate.)

3. Visually check the door and cavity face plate for damage

(dents, cracks, signs of arcing etc.).

Carry out any remedial work that is necessary before oper-
ating the oven.
Do not operate the oven if any of the following conditions
exist;

Please refer to ‘OVEN PARTS, CABINET PARTS, DOOR PARTS’, when carrying out any of the following removal
procedures:

To remove the outer case, proceed as follows.
1. Disconnect oven from power supply.
2. Open the oven door and wedge it open.
3. Remove the screws from rear and along the side edge of

case.

4. Slide the entire case back about 3cm to free it from

retaining clips on the cavity face plate.

5. Lift the entire case from the oven.

6. Discharge the H.V. capacitor before carrying out any

further work.

7. Do not operate the oven with the outer case removed.
N.B.; Step 1, 2 and 6 form the basis of the 3D checks.

CAUTION: DISCHARGE HIGH VOLTAGE

CAPACITOR BEFORE TOUCHING ANY
OVEN COMPONENTS OR WIRING.

To remove the components, proceed as follows.

1. CARRY OUT 3D CHECKS
2. Disconnect all the leads and terminals of high voltage

rectifier assembly from high voltage capacitor.

3. Remove one (1) screw holding earth side terminal of high

voltage rectifier assembly, and remove capacitor holder.

4. Remove one (1) screw holding capacitor holder to the

oven cavity.

5. Release the capacitor holder from the duct.

6. Remove the capacitor from the capacitor holder.
7. Now high voltage rectifier assembly and capacitor should

be free.

CAUTION: WHEN REPLACING HIGH VOLTAGE

RECTIFIER ASSEMBLY, ENSURE THAT
THE CATHODE (EARTH) CONNECTION IS
SECURELY FIXED TO THE CAPACITOR
HOLDER WITH AN EARTHING SCREW.

1. CARRY OUT 3D CHECKS
2. Disconnect the filament leads of the power transformer

from high voltage capacitor and the magnetron.

3. Disconnect the H.V. wire A from the power transformer.
4. Disconnect the main wire harness from the power

1. CARRY OUT 3D CHECKS.
2. Remove the air separate duct from the chassis support

and the air intake duct.

3. Disconnect the H.V. wire B and filament lead of the

transformer  from the magnetron.

4. Remove the one (1) screw holding the chassis support to

the magnetron.

5. Move the air intake duct to left.
6. Remove the air deflector from the magnetron.
7. Carefully remove four (4) screws holding magnetron to

waveguide, when removing the screws hold the
magnetron to prevent it from falling.

8. Remove the magnetron from the waveguide with care so

that the magnetron antenna is not hit by any metal object
around the antenna.

9. Remove the magnetron cushion from the magnetron.

CAUTION: WHEN REPLACING THE MAGNETRON, BE

SURE THE R.F. GASKET IS IN PLACE AND
THE MAGNETRON MOUNTING SCREWS
ARE TIGHTENED SECURELY.