Kenmore 721.63662 Service Manual page 30

(3) CHECKOUT PROCEDURES FOR CIRCUIT
BOARD
The following symptoms indicate a defective circuit
board.
1) Check the input current. If the input current is more
than 20A, check the magnetron and wiring. If the
input current is less than 0.5 A, there is no input to
the inverter.
2) The start function fails to operate but the high
voltage Systems, the interlock switches, the door
sensing and the relay check good.
3) The unit with a normal relay continuously operates.
4) The buzzer does not sound or continues to sound.
NOTE: A MICROWAVE ENERGY LEAKAGE TEST MUST ALWAYS BE PERFORMED WHEN THE UNIT IS
SERVICED FOR ANY REASON.
5) Some segments of one or more digits do not light
up, or they continue to light up, or segments light
when they should not.
6) Wrong figures appear.
7) The figures of all digits.
8) The clock does not keep time properly.
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