R-27STM
3
WARNING TO SERVICE PERSONNEL
Microwave ovens contain circuitry capable of producing very high voltage and current, contact with any part of the high voltage circuit
will result in electrocution. High voltage capacitor, Power transformer, Magnetron, High voltage rectifier assembly, High voltage fuse,
High voltage harness.
REMEMBER TO CHECK
3D
Disconnect the supply.
Door opened, and wedged open.
Discharge the high voltage capacitor.
WARNING: AGAINST THE CHARGE OF THE HIGH-VOLT-
AGE CAPACITOR
The high-voltage capacitor remains charged about 60
seconds after the oven has been switched off. Wait for
60 seconds and then short-circuit the connection of the
high-voltage capacitor (that is, of the connecting lead of
the high-voltage rectifier) against the chassis with the
use of an insulated screwdriver.
Sharp recommend that wherever possible fault-finding is car
-
ried out with the supply disconnected. It may, in some cases,
be necessary to connect the supply after the outer case has
been removed, in this event carry out 3D checks and then
disconnect the leads to the primary of the power transformer.
Ensure that these leads remain isolated from other compo -
nents and the oven chassis. (Use insulation tape if neces -
sary.) When the testing is completed, carry out 3D checks and
reconnect the leads to the primary of the power transformer.
REMEMBER TO CHECK
4R
Reconnect all leads removed from components during testing.
Replace the outer case (cabinet).
Reconnect the supply.
Run the oven. Check all functions.
Microwave ovens should not be run empty. To test for the
presence of microwave energy within a cavity, place a cup of
cold water on the oven turntable, close the door and set the
power level to HIGH (100%). And set the microwave timer for
two (2) minutes. When the two minutes has elapsed (timer at
zero) carefully check that the water is now hot. If the water re
-
mains cold, carry out 3D checks and re-examine the connec
-
tions to the component being tested.
When all service work is completed and the oven is fully assembled, the microwave power output should be checked and microwave
leakage test should be carried out.
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11/3/08 2:04:24 PM
