Panasonic NN-V659WB Service Manual page 22

Alternative way to troubleshooting oven with AC Ampare meter used.
Oven shuts down after approximately 15 or 33 seconds.
If the microwave oven shuts down after a short time in micropower mode, conduct the following test.
The microwave oven must be set in test mode to activate the self diagnostic failure code system.
SELF TEST MODE
DELAY/
CLOCK
STAND
When oven is set in test mode place water load in oven, set micropower to high and time to 1 minute, press start.
H97, H98 appears in display window a short time after start key is pressed and no microwave oscillation with AC Ampare meter
used for troubleshooting.
H97, H98 appears in the
display window
Check oven input AC am-
pares measure at oven plug
more than 0.5A
Check magnetron filament
continuity
refer to component
OK
test procedures
HIGH POW ER
START
DANGER
HIGH
VOLTAGE
DPC board/Power Delay
less than 0.4A
Loose wiring
Latch switch
DPC control signal
Open
Magnetron*
NOTE: If filament is opened, it
will flow AC input Ampare 0.5 - 1A
STOP!!
If all the above is OK up
to this point, there may
be a H.V. Inverter problem
(SEE NOTE)
NEW H.V.
DISPLAY
DISPLAY
4N50BPQ
4N30BPQ
NN-V689W B
NOTE:
DO NOT try to REPAIR this Inverter Power Supply(U)
and also DO NOT RE-ADJUST PRESET VOLUME
on the board. It is very dangerous to repair or adjust
without sufficient test equipment because this circuit
handles very high voltage and very large current. Off
alignment of inverter board operation is dangerous.
Operating a misaligned Inverter circuit is dangerous
due to the very high voltage and current that is
produced by this board. Defective boards must be
replaced with a new one.
*Check magnetron filament for open or short to casing before
proceeding to determine a good magnetron.
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