Component Replacement And Adjustment Procedure - Sharp R-90GCH Service Manual

R-90GCH

COMPONENT REPLACEMENT AND ADJUSTMENT PROCEDURE

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, High Voltage 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 oven from power supply.
2. Make sure that a definite" click" can be heard when
the microwave oven door is unlatched. (Pull down the
door handle in a closed position with one hand, then
push the door 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
operating the oven.
Do not operate the oven if any of the following conditions
exist;
To prevent an electric shock, take the following
precautions.
1. Before wiring,
1) Disconnect the oven from power supply.
2) Open the door and wedge the door open.
3) Discharge the 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, High voltage transformer, High voltage
capacitor and High voltage rectifier assembly.
2) Hot parts:
Oven lamp, Magnetron, High voltage transformer,
Oven cavity and Heating element.
Please refer to 'OVEN PARTS, CABINET PARTS, CONTROL PANEL PARTS, DOOR PARTS', when carrying out any
of the following removal procedures:
1. Disconnect the oven from power supply.
2. Open the oven door and wedge the door open.
3. Remove the four (4) screws holding the exhaust cover
to the back plate and the outer case cabinet.
4. Remove the three (3) screws holding the outer case
cabinet to the back plate.
5. Remove the four (4) screws holding the right and left
sides of the outer case cabinet to the bottom plate.
6. Slide the entire outer case cabinet back out about 1
inch (3cm) to free it from retaining clips on the oven
cavity front plate.
WARNING AGAINST HIGH VOLTAGE:
WARNING FOR WIRING
OUTER CASE REMOVAL
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.
3) Sharp edge:
Bottom plate, Oven cavity, Waveguide flange,
Chassis support and other metallic plate.
4) Moveable parts (to prevent a fault)
Fan blade, Fan motor, Switch, Door cam,
Convection motor, Convection fan, Turntable
motor, Damper motor, Damper door assembly.
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.
7. Lift entire outer case cabinet from the unit.
8. Discharge the H.V. capacitor before carrying out any
further work.
9. Do not operate the oven with the outer case removed.
N.B.; Step 1, 2 and 8 form the basis of the 3D checks.
CAUTION
1. DISCONNECT THE OVEN FROM THE POWER
SUPPLY BEFORE REMOVING THE OUTER CASE
CABINET.
2. DISCHARGE THE HIGH VOLTAGE CAPACITOR
BEFORE TOUCHING ANY OVEN COMPONENTS
OR WIRING.
28