Chapter 9. Component Replacement And Adjustment Procedure Warnings; Adjustment Procedure 1] Warnings; Outer Case And Rear Cover Removal - Sharp R-1900J Service Manual

CHAPTER 9.
R1900J
COMPONENT REPLACEMENT AND ADJUSTMENT PROCEDURE
[1] WARNINGS
Microwave ovens contain circuitry capable of producing very high voltage and current, contact with following parts may result
in severe, possibly fatal, electric shock.
(Example)
High Voltage Capacitor, Power Transformer, Magnetron, High Voltage Rectifier Assembly, High Voltage Harness etc..
Avoid possible exposure to microwave energy. Please follow the instructions below before
WARNING:
operating the oven.
1. Disconnect the power supply cord.
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 pull the door handle
lever with the other, this causes the latch leads 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 operat-
ing the oven.
Do not operate the oven if any of the following conditions exist;
1. Door does not close firmly.
To prevent an electric shock, take the following precau-
tions.
1. Before wiring,
1) Disconnect the power supply cord.
2) Open the door block it open.
3) Discharge the two high voltage capacitor and wait for
60 seconds.
2. Don't let the wire leads touch to the following parts;
1) High voltage parts:
Magnetron, Power transformer, High voltage
capacitor, High voltage rectifier assembly and High
voltage wire.
2) Hot parts:
Oven lamp, Magnetron, Power transformer and
Please refer to "OVEN PARTS, CABINET PARTS, CONTROL PANEL PARTS, DOOR PARTS", when carrying out any of the following removal proce-
dures:

[2] OUTER CASE AND REAR COVER REMOVAL

To remove the components, procedure as follows.
1. Disconnect the oven form the power supply.
2. Open the door and wedge it open.
3. Remove the eleven (11) screws from the rear and along side the
edge of the outer case.
NOTE: Do not lose the support angle at this time.
4. Slide the case back about 1 inch (3 cm) to free it from the oven cav-
ity.
5. Lift entire case from the unit.
WARNING AGAINST HIGH VOLTAGE:
WARNING FOR WIRING
9 – 1
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.
Oven cavity.
3) Sharp edge:
Bottom plate, Oven cavity, Waveguide flange Chassis
support and other metallic plate.
4) Movable parts (to prevent a fault)
Blower fan blade, Blower fan motor, Switches, Switch
levers, Antenna motor and Stirrer antennas.
3. Do not catch the wire leads in the outer case cabinet.
4. Insert the positive lock connector until its pin is locked and
make sure that the wire leads do not come off even if the
wire leads are pulled.
5. To prevent an error function, connect the wire leads
correctly, referring to the Pictorial Diagram.
6. DISCHARGE TWO HIGH VOLTAGE CAPACITORS BEFORE
TOUCHING ANY OVEN COMPONENTS OR WIRING.
7. Now, outer case is free.
NOTE: Step 1, 2 and 6 form the basis of the 3D checks.
To remove rear cover:
8. Remove the four (4) screws holding the magnetron exhaust cover
to the rear cover.
NOTE: The magnetron exhaust cover can not be removed from the
rear cover.
9. Disconnect the connector of the fan motor from the connector of
harness.
R1900J