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NN-G55 AR
COMPONENT TEST PROCEDURE
CAUTION
1. High voltage is present at the high voltage terminal of the High
Voltage Inverter (U) including aluminum heat sink during any
cook cycle.
2. It is neither necessary nor advisable to attempt mea-surement
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.
1. Primary Latch Switch, Secondary (Secondary Latch
Switch and Power Relay B) Interlocks.
(A) Unplug the lead connectors to Power Relay B and verify
continuity of the power relay B 1-2 terminals.
(B) Unplug lead connectors to Primary Latch Switch and
Secondary Latch Switch.
(C) Test the continuity of switches at door opened and closed
positions with ohm meter (low scale).
Normal continuity readings should be as follows:
2. Short Switch & Monitor
(A) Unplug lead wires from Inverter Power Supply (U) primary
terminals.
(B) Connect test probes of ohm meter to the disconnected leads
which were connected to Inverter Power Supply (U).
(C) 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.
3. Magnetron
Continuity checks can only indicate an open filament or a
shorted magnetron. To diagnose for an open filament or
shorted magnetron.
(A) Isolate magnetron from the circuit by disconnecting the leads.
(B) A continuity check across magnetron filament terminals
should indicate one ohm or less.
(C) A continuity check between each filament terminal and
magnetron case should read open.
Door opened
0
Ω
Door closed
∞Ω
Door Closed
0
Ω
(close)
0
Ω
(close)
∞Ω
(open)
Porta Aberta
∞Ω
(open)
∞Ω
(open)
∞Ω
(open)
Primary latch switch
Secundary latch switch
Relay
ANTENNA
MAGNETRON
CASE
HIGHEST OHM
SCALE
FILAMENT TERMINALS
0
Ω
~ 1
Ω
R x 1 SCALE
4. Membrane key board (Membrane switch assembly)
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.
5. Inverter Power Supply
DANGER HIGH VOLTAGE
Test if failure codes of H97 or H98 appears by doing the following
procedure. It is recommended to use an AC line input current
Ampere meter for testing.
TEST 1
(A) Unplug 2 pin HV connector CN703.
(B) Program DPC: (Press the keys below in the sequence)
1. Press TIEMPO 2 times.
2. Press ENCENDER.
3. Press POTENCIA.
(C) Place 1 liter of water load into oven cavity.
(D) Program oven at High power for 1 minute and press
ENCENDER.
1. After approximately 15 seconds, oven displays H98 and
stops oven.
2. During oven operation, input current is approximately 1.0
to 1.7A. If both 1 and 2 are OK, please proceed to Test 2.
TEST 2
(A) Unplug 3 pin connector CN701, CN703 remain unpluged.
(B) Program DPC: (Press the keys below in the sequence)
1. Press TIEMPO 2 times.
2. Press ENCENDER.
3. Press POTENCIA.
(C) Place 1 liter of water load into oven cavity.
(D) Program oven at High power for 1 minute and press
ENCENDER.
1. After approximately 27 seconds, oven displays H97 and stops
oven.
2. During oven operation, input current is approximately 0.4 to
0.8A.
If both tests are OK, the Inverter Power Supply can be determined
OK.
