R-252M (serv.man2) - Sharp Home Appliance Service Manual (repair manual). Page 18

R-252M   18

1. Disconnect oven from power supply.
2. Visually check the door and cavity face plate for dam-

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

Carry out any remedial work that is necessary before
operating the oven.
Do not operate the oven if any of the following conditions
exist;
1. Door does not close firmly.
2. Door hinge, support or latch hook is damaged.
3. The door gasket or seal or 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.

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

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

further work.

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

CAUTION: DISCHARGE HIGH VOLTAGE CAPACI-

TOR BEFORE TOUCHING ANY OVEN
COMPONENT OR WIRING.

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 3 cm to free it from

retaining clips on the cavity face plate.

5. Lift the entire case from the oven.

7. Now, the high voltage rectifier and the capacitor should

be free.

CAUTION: WHEN REPLACING HIGH VOLTAGE REC-

TIFIER, ENSURE THAT THE CATHODE
(EARTH) CONNECTION IS SECURELY
FIXED TO THE CAPACITOR HOLDER AND
BASE PLATE WITH AN EARTHING
SCREW.

To remove the components, proceed as follows.
1. CARRY OUT 3D CHECKS.
2. Disconnect all the leads and the terminal of high

voltage rectifier from the high voltage capacitor.

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

the high voltage rectifier and remove the capacitor
holder from the base plate.

4. Remove the capacitor from the capacitor holder.

Ensure the following:

1. Wires must not touch:

a) High voltage parts.
    (Magnetron, high voltage transformer, high voltage capacitor and high voltage rectifier assembly)
b) Parts that become hot.
    (Heating elements, oven lamp, oven cavity magnetron and high voltage transformer)
c) Sharp edges.
    (Bottom plates, oven cavity, waveguide flange, chassis support and other metallic parts)
d) Movable parts.
    (Fan blade, any motor, switch, switch lever and open button)

2. Positive lock connectors are fitted correctly.
3. Wires are connected correctly as per pictoral diagram.
4. No wire leads are trapped by the outer wrap.

WARNING: WIRING/RE-WIRING
Before carrying out any work; carry out 3D checks.
1. Disconnect the supply.
2. Door opened, and wedged open.
3. Discharge the high voltage capacitor.