Component Test Procedure; Primary Latch Switch, Secondary (Secondary Latch Switch And Power Relay B) Interlocks; Short Switch & Monitor Circuit; Magnetron - Panasonic NN-V359WB Service Manual

7.

COMPONENT TEST PROCEDURE

CAUTION
1. High voltage is present at the high voltage terminal of the
High Voltage Inverter(U) including aluminium heat sink
during any cook cycle.
2. It is neither necessary nor advisable to attempt
measurement of the high voltage.
3. Before touching any oven components, or wiring, always
unplug the oven from its power source and discharge the
high voltage capacitors.
7.1 Primary Latch Switch, Secondary
(Secondary Latch Switch and Power
Relay B) Interlocks.
1. Unplug the lead connectors to Power Relay B and verify
continuity of the power relay B 1-2 terminals.
2. Unplug lead connectors to Primary Latch Switch and
Secondary Latch Switch.
3. Test the continuity of switches at door opened and closed
positions with ohm meter (low scale).
Normal continuity readings should be as follows.
Primary Latch Switch
Secondary Latch Switch
Power Relay B
7.2 Short Switch & Monitor Circuit
1. Unplug lead wires from H.V. Inverter primary terminals.
2. Connect test probes of ohm meter to the disconnected leads
which were connected to H.V. Inverter.
3. Test the continuity of short switch with door opened and
closed positions using lowest scale of the ohm meter.
Normal continuity readings should be as follows.
Door Opened
0 Ω
ANTENNA
ANTENNA
GASKET

MAGNETRON

CASE
HIGHEST
OHM
Ω
SCALE
NEW H.V.
Door Opened Door Closed
Ω (open) 0 Ω (close)
Ω (open) 0 Ω (close)
Ω (open) Ω (close)
NEW H.V.
Door Closed
Ω
COOLING FIN
0 Ω − 1 Ω
RX1
SCALE
FILAMENT
TERMINALS
04-031M
7.3 Magnetron
Continuity checks can only indicate an open filament or a
shorted magnetron. To diagnose for an open filament or shorted
magnetron.
1. Isolate magnetron from the circuit by disconnecting the leads
2. A continuity check across magnetron filament terminals
should indicate one ohm or less.
3. A continuity check between each filament terminal and
magnetron case should read open.

7.4 Push button key board

Check continuity between switch terminals, by tapping an
appropriate pad on the key board. The contacts assignment of
the respective pads on the key board is as shown in digital
programmer circuit (schematic).
15