Sharp R-4H55 Service Manual page 29

R-4H55
R-4X55
R-4X55B
COMPONENT REPLACEMENT AND ADJUSTMENT PROCEDURE
WARNING: AVOID POSSIBLE EXPOSURE TO MICROWAVE ENERGY. PLEASE FOLLOW THE INSTRUC-
TIONS BELOW .BRBEFORE OPERATING THE OVEN.
1
1. CARRY OUT 3D CHECKS.
2. Make sure that a definite "click" can be heard when the
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 heads to rise, it is then pos-
sible to hear a "click" as the door switches operate.)
3. Visually check the door and cavity face plate for dam-
age (dents, cracks, signs of arcing etc.).
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:
Carry out any remedial work that is necessary before oper- 1. Without the RF gasket (Magnetron).
ating the oven.
2. If the wave guide or oven cavity are not intact.
Do not operate the oven if any of the following conditions
exist
3. If the door is not closed.
4. If the outer case (cabinet) is not fitted.
1. Door does not close firmly.
Please refer to 'OVEN PARTS, CABINET PARTS, DOOR PARTS', when carrying out any of the following removal proce-
dures:
OUTER CASE REMOVAL
To remove the outer case, proceed as follows.
6. Discharge the H.V. capacitor before carring out any
1. Disconnect oven from power supply.
further work.
2. Open the oven door and wedge it open.
7. Do not operate the oven with the outer case removed.
3. Remove the screws from rear and along the side edge
N.B.; Step 1,2 and 6 from the basis of the 3D checks.
of case.
4. Slide the entire case back about 1 inch(3 cm) to free it
from retaining clips on the cavity face plate.
5. Lift the entire case from the oven.
CAUTION: DISC
11.--- I..-.. .,-.-1-- -.-.I.
TOH Ott-u
COMPONEI
JHAHtit HltiH VULI Atit C;Al-'AC;I-
. ---A
IRE TOUCHING ANY OVEN
ITS OR WIRING.
POWER TRANSFORMER REMOVAL
1. CARRY OUT 3D CHECKS
2. Remove the fan motor assembly from the oven refer-
ring to "FAN MOTOR ASSEMBLY".
3. Disconnect the filament lead of the power transformer
from high voltage capacitor.
4. Disconnect the filament lead of the power transformer
from the magnetron.
5. Disconnect the high voltage wire of H.V. rectifier as-
sembly from the power transformer.
6. Remove the one (1) screw from under side and two (2)
screws from upper side holding the transformer to bot-
tom plate.
7. Remove the transformer.
HIGH VOLTAGE COMPONENTS REMOVAL
(HIGH VOLTAGE CAPACITOR AND HIGH VOLTAGE RECTIFIER ASSEMBLY)
To remove the components, proceed as follows.
1. CARRY OUT ;.us on;3D;.us off; CHECKS
2. Disconnect the high voltage wire A from the magnetron.
3. Disconnect the filament lead(shorter one) of the power
transformer.
4. Disconnect the high voltage wire of the H.V. rectifier
assembly from the high voltage capacitor.
holder from the high voltage capacitor.
7. Disconnect high voltage wire A and terminals of high
voltage rectifier assembly from high voltage capacitor.
8. Now high voltage rectifier assembly and capacitor
should be free.
5. Remove one (1) screw holding capacitor holder to the
oven cavity.
6. Remove one (1) screw holding earth side terminal of
high voltage rectifier assembly, and remove capacitor
CAUTION: WHEN REPLACING HIGH VOLTAGE
RECTIFIER ASSEMBLY, ENSURE THAT
THE CATHODE (EARTH) CONNECTION
IS SECURELY FIXED TO THE CAPACI-
TOR HOLDER WITH AN EARTHING
SCREW.
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