Chapter 11. Component Replacement And Adjustment Procedure Before Operating; Outer Case Removal; High Voltage Transformer Removal - Sharp R-239 Service Manual

R239(W)
CHAPTER 11.
R239(W)
COMPONENT REPLACEMENT AND ADJUSTMENT PROCE-
DURE
[1] BEFORE OPERATING
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 fuse, High Voltage Harness etc..
Avoid possible exposure to microwave energy. Please follow the instructions below before operating
WARNING:
the oven.
1) Disconnect the power supply cord.
2) 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;
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.
To prevent an electric shock, take the following manners.
1. Before wiring,
1) Disconnect the power supply cord.
2) Open the door and block it 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,
High voltage rectifier assembly and High voltage fuse.
2) Hot parts:
Oven lamp, Magnetron, High voltage transformer and Oven
cavity.
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 oven from power supply.
2. Open the oven door and wedge it open.
3. Remove the two (2) screws from right side of the outer case cabi-
net.
4. Remove the five (5) screws from rear and along the side edge of
case.

[3] HIGH VOLTAGE TRANSFORMER REMOVAL

1. CARRY OUT 3D CHECKS.
WARNING AGAINST HIGH VOLTAGE:
WARNING FOR WIRING
REMEMBER TO CHECK 3D
1) Disconnect the supply.
2)Door opened, and wedged open.
Service Manual
5) There are defective parts in the door interlock system.
6) There are defective parts in the microwave generating and trans-
mission 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 and other metallic
plate.
4) Movable parts (to prevent a fault)
Fan blade, Fan motor, Turntable motor and Switch.
3. Do not catch the wire leads in the outer case cabinet.
4. Insert the positive lock connector certainly 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, refer-
ring to the Pictorial Diagram.
3)Discharge high voltage capacitor.
5. Slide the entire case back about 3cm to free it from retaining clips
on the cavity face plate.
6. Lift the entire case from the oven.
7. Discharge the H.V. capacitor before carrying out any further work.
8. Do not operate the oven with the outer case removed.
NOTE: Step 1, 2 and 7 form the basis of the 3D checks.
CAUTION: DISCONNECT OVEN FROM POWER SUPPLY BEFORE
REMOVING OUTER CASE.
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