Power Transformer Removal; High Voltage Rectifier Assembly And High Voltage Capacitor Removal; Magnetron Removal; Control Panel Assembly Removal - Sharp R-21LTF Service Manual

R21LTF

[3] POWER TRANSFORMER REMOVAL

1. Disconnect the power supply cord and remove outer case.
2. Open the oven door and block it open.
3. Discharge high voltage capacitor.
4. Disconnect the filament leads of power transformer from high volt-
age capacitor and the magnetron.
5. Disconnect the H.V. wire from the power transformer.

[4] HIGH VOLTAGE RECTIFIER ASSEMBLY AND HIGH VOLTAGE CAPACITOR REMOVAL

To remove the components, proceed as follows.
1. Disconnect the power supply cord and remove outer case.
2. Open the oven door and block it open.
3. Discharge high voltage capacitor.
4. Disconnect H.V. wire of the high voltage rectifier assembly from the
magnetron and the power transformer.
5. Disconnect the filament lead of the power transformer from the high
voltage capacitor.
6. Remove one (1) screw holding earth side terminal of the high volt-
age rectifier assembly.
7. Disconnect all the leads and terminals of high voltage rectifier
assembly from the high voltage capacitor.

[5] MAGNETRON REMOVAL

1. Disconnect the power supply cord and remove outer case.
2. Open the oven door and block it open.
3. Discharge high voltage capacitor.
4. Disconnect the high voltage wire of the high voltage rectifier
assembly and filament lead of the transformer from the magnetron.
5. Remove the one (1) screw holding the airguide to the magnetron
and remove the airguide.
6. Remove the one (1) screw holding the insertion plate A to the mag-
netron and remove the insertion plate A.
7. Remove the one (1) screw holding the chassis support to the mag-
netron.

[6] CONTROL PANEL ASSEMBLY REMOVAL

CONTROL PANEL ASSEMBLY
1. Disconnect the power supply cord and remove outer case.
2. Open the door and block it open.
3. Discharge high voltage capacitor.
4. Disconnect the main wire harness from the control unit.
5. Remove the one (1) screw holding the control panel assembly to
the oven cavity front plate.
6. Lift up the control panel assembly.
7. Now, the control panel assembly is free.
6. Disconnect the main wire harness from the power transformer.
7. Remove the two (2) screws and two (2) VCP caps holding the
transformer to base plate.
8. Remove the transformer.
9. Now the power transformer is free.
8. Now, the high voltage rectifier assembly should be free.
9. Remove one (1) screw holding the capacitor holder to the oven
cavity rear plate.
10.Remove one (1) screw holding the fan duct to the oven cavity rear
plate.
11. Release the capacitor holder from the fan duct.
12.Remove the capacitor from the capacitor holder.
13.Now, the capacitor should be free.
CAUTION: WHEN REPLACING HIGH VOLTAGE RECTIFIER AND
HIGH VOLTAGE CAPACITOR, GROUND SIDE TERMI-
NAL OF THE HIGH VOLTAGE RECTIFIER MUST BE
SECURED FIRMLY WITH A GROUNDING SCREW.
8. Release the tabs of air intake duct from the chassis support and the
oven cavity.
9. Move the air intake duct to the left.
10.Carefully remove four (4) screws holding magnetron to waveguide,
when removing the screws hold the magnetron to prevent it from
falling.
11. Remove the magnetron from the waveguide with care so the mag-
netron antenna is not hit by any metal object around the antenna.
CAUTION: WHEN REPLACING THE MAGNETRON, BE SURE THE
R.F. GASKET IS IN PLACE AND THE MAGNETRON
MOUNTING SCREWS ARE TIGHTENED SECURELY.
CONTROL UNIT
8. Disconnect the flat ribbon cable from the connector CN-G.
9. Remove the six (6) screws holding the control unit to the control
panel frame.
10.Release the two (2) tabs of the control panel frame holding the con-
trol unit to the control panel frame.
11. Now, the control unit is free.
NOTE: 1) Before attaching a new key unit, wipe off remaining adhe-
sive on the control panel frame surfaces completely with a
soft cloth soaked in alcohol.
2) When attaching the key unit to the control panel frame,
adjust the upper edge and right edge of the key unit to the
correct position of control panel frame
3) Stick the key unit firmly to the control panel frame by rub-
bing with a soft cloth so not to cause scratches.
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