Sharp R-3A88, Service Manual

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18
R-3A88
COMPONENT REPLACEMENT AND ADJUSTMENT PROCEDURE
WARNING: Avoid possible exposure to microwave energy. Please follow the instructions below before
operating the oven.
1. Door does not close firmly.
2. Door hinge, support or latch hook is damaged.
3. The door gasket or seal or 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.
1. Disconnect oven from power supply.
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
operating the oven.
Do not operate the oven if any of the following conditions
exist;
Please refer to ‘OVEN PARTS, CABINET PARTS, CONTROL PANEL PARTS, DOOR PARTS’, when carrying out any of
the following removal procedures:
OUTER CASE REMOVAL
To remove the outer case proceed as follows.
1. Disconnect oven from power supply.
2. Open the oven door and wedge it open.
3. Remove the six (6) screws from rear and along the right
side edge of case.
4. Slide the entire case back about 3cm to free it from
retaining clips on the cavity face plate.
5. Lift the entire case from the unit.
6. Discharge the H.V. capacitor before carrying out any
further work.
7. Do not operate the oven with the outer case removed.
N.B.; Step 1, 2 and 7 form the basis of the 3D checks.
CAUTION: DISCHARGE HIGH VOLTAGE CAPACITOR
BEFORE TOUCHING ANY OVEN COMPONENT
OR WIRING.
MAGNETRON REMOVAL
4. Re-install outer case and check that the oven is operating
properly.
CAUTION: WHEN REPLACING MAGNETRON, BE SURE
THE R.F. GASKET IS IN PLACE AND MOUNT-
ING SCREWS ARE TIGHTENED SECURELY
Removal
1. CARRY OUT 3D CHECKS.
2. Disconnect wire leads from magnetron.
3. Remove the two (2) screws holding chassis support to
oven cavity front plate and magnetron.
4. Remove the chassis support from oven.
5. Carefully remove the two (2) screws holding magnetron
to waveguide flange.
6. Lift up magnetron with care so that magnetron antenna
is not hit by any metal object around antenna.
7. Now, the magnetron is free.
Re-install
1. Re-install the magnetron to waveguide flange with the
two (2) screws diagonally as shown in Figure C-1.
2. Re-install the chassis support to oven cavity front plate
and magnetron with the two (2) screws.
3. Reconnect the wire leads to the magnetron. Refer to
"PICTORIAL DIAGRAM".
Figure C-1. Magnetron replacement
WAVEGUIDE
FLANGE
SCREWS
MAGNETRON
POWER TRANSFORMER REMOVAL
1. CARRY OUT 3D CHECKS.
2. Disconnect wire leads from power transformer,
magnetron and capacitor terminals.
3. Remove four (4) screws holding transformer to bottom