Sharp R-7280 - Component Replacement and Adjustment; Outer Case and High Voltage Components Removal; Power Transformer and Magnetron Removal

R-7280
R-1720
COMPONENT REPLACEMENT AND ADJUSTMENT PROCEDURE
WARNING: To avoid possible exposure to microwave
energy;
A. Before operating oven
1. Make sure that unlatching door slowly is ac-
companied by a click indicating actuation of
monitor switch and latch switch.
2.
Check visually door seal for arcing and damage.
B. Do not operate oven until after repair if any of fol-
lowing conditions exist;
1. Door does not close firmly against front of ap-
pliance.
2. There is a broken door hinge or support.
3. The door is bent or warped.
4. There is any defective parts in the latch, oven
door or microwave generating and transmission
assembly.
5. There is any other visible damage to oven.
C. Do not operate oven
1. Without the RF gasket.
2. If door is not closed.
( RDA1204U)
OUTER CASE REMOVAL
::
3.
To remove the comoonents. proceed as follows.
Disconnect oven’ from power supply.
Remove screws from rear and along the side edge
of case.
Slide the entire case back about 3cm to free it from
retaining clips on the cavity face plate.
4. Lift entire case from the unit.
CAUTION: DISCHARGE HIGH VOLTAGE
CAPACITOR BEFOR TOUCHING ANY
OVEN COMPONENTS OR WIRING.
1.
2.
3.
4.
1.
2.
3.
1.
2.
3.
4.
5.
6.
HIGH VOLTAGE COMPONENTS REMOVAL
(HIGH VOLTAGE CAPACITOR AND RECTIFIER AND SHORT PROTECTOR)
To remove the components, proceed as follows.
Disconnect oven from power supply and remove the
outer case.
Discharge high voltage capacitor.
Remove one (I ) screw holding capacitor holder to
oven unit.
Remove one (1) screw holding earth side terminal
of rectifier, and remove capacitor holder.
5. Disconnect wire leads and terminal of rectifier from
high voltage capacitor. Now, rectifier is free.
6. Disconnect terminals of short protector from high
voltage capacitor.Now, capacitor is free.
CAUTION:
WHEN REPLACING RECTIFIER, EARTH
SIDE TERMINAL MUST BE SECURED
FIRMLY WITH A EARTHING SCREW.
POWER TRANSFORMER REMOVAL
Disconnect oven from power supply and remove
outer case.
Discharge high voltage capacitor.
Disconnect wire leads from power transformer
4. Disconnect filament leads from magnetron and high
voltage capacitor.
5. Remove two (2) screws holding transformer to unit
chassis.
6. Remove power transformer.
MAGNETRON REMOVAL
Disconnect oven from power supply and remove
outer case.
Discharge high voltage capacitor.
Disconnect wire leads from magnetron.
Remove one (I ) screw holding air duct.
Carefully loosen four (4) screws holding magnetron
to waveguide flange.
Lower magnetron assembly until tube is clear of the
wavegu ide.
1. Re-install magnetron to waveguide flange by the
four (4) mounting screws.
2. Install air duct to magnetron by one (1) mounting
screw.
3. Re-connected wire leads to magnetron.
CAUTION:
WHEN REPLACING THE MAGNETRON,
BE SURE THE R.F. GASKET IS IN
PLACE AND MAGNETRON MOUNTING
Re- install
SCREWS ARE TIGHTENED SECURELY.
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