R420LW
11 – 1
R420LW
Service Manual
CHAPTER 11.
COMPONENT REPLACEMENT AND ADJUSTMENT PROCE-
DURE
[1] WARNINGS
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 REMOVAL
To remove the outer case, procedure as follows.
1. Disconnect the power supply cord.
2. Open the oven door and block it open.
3. Remove the two (2) screws from the lower portion of the rear cabi-
net using a T20H Torx type or GTXH20-100 screw driver.
4. Remove the remaining two (2) screws from rear.
5. Slide the entire outer case back out about 1 inch (3 cm) to free it
from retaining clips on the cavity face plate.
6. Lift entire outer case from the unit.
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..
WARNING:
Avoid possible exposure to microwave energy. Please follow the instructions below before
operating the oven.
WARNING AGAINST HIGH VOLTAGE:
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 push the door open
button 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.
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.
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) Wait for 60 seconds, then discharge the high voltage
capacitor.
2. Do not 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, Power transformer and Oven
cavity.
WARNING FOR WIRING
3) Sharp edge:
Bottom plate, Oven cavity, Waveguide flange,
Chassis support and other metallic plate.
4) Movable parts (to prevent a fault)
Fan blade, Fan motor, Switch, Switch lever, Open
button.
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.
