Panasonic NE-7910 Service Manual page 33

(B)
(C)
(A)
(B)
(C)
(D)
(E)
A continuity check across magnetron filament terminals
should indicate one ohm or less.
A continuity check between each filament terminal and
magnetron case should read open.
Variable power switch
Isolate the variable power switch from the circuit by
disconnecting all leads and check continuity.
A continuity check across the switch coil should be
about 200 ohms.
A continuity check between switch terminals should
read open.
A continuity check between each switch terminal and
ground should read open.
In order to check if the contacts of the variable power
switch are operating normally, do the following test
procedure.
* Follow the procedure on page 20 for measuring the
diode current.
Now select a power other than high and start the
oven.
Observe the diode current and youcan tell ifthe switch
contacts are operating and closing.
follow the chart in Fig. 37 on page 31 to
help
you determine
if the variable
power
switch
contacts are
working properly.
Low voltage transformer
The low voltage transformer is located in lower side of
the digital programmer circuit.
Remove lead wire connector of the low voltage trans-
former from lead wire harness and check continuity.
Normal reading of primary winding is
about 90 — 110 ohm.
Magnetron
Chassis Ground
Antenna
Embossed Ring.
Filament
Terminals
MAGNETRON
(Fig. 39)
Switch Terminal
Metal Ground
Coil Terminals
Switch Terminal
VARIABLE POWER SWITCH
(Fig. 40)
Low voltage transformer
(Fig. 41)