Panasonic NN-GD356W, Service Manual

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5.5. Inverter power supply (U)
DO NOT try to REPAIR H.V. Inverter power supply
(U).Replace complete H.V. Inverter(U) Unit.
DANGER HIGH VOLTAGE
Test if failure codes of H95, H97 or H98 appear by doing the
following procedure. It is recommended to use an AC line input
current Ampere meter for testing.
Test1
1. Program DPC.
a. Tap Reheat pad once.
b. Tap 10 min. pad thrice.
2. Place 1 liter of water load into oven cavity.
3. Unplug 2 pin H.V. lead wire connector CN703 from
magnetron tube.
4. Program oven at High power for 1 minute and press start.
a. After approximately 23 seconds, oven stops.
b. During oven operation, input current is approximately
0.5 to 1A. If both a and b are OK, proceed to test 2.
INPUT AMPERE FAILURE CODE
Unplug CN703 0.5 to 1A Oven stops in 23
seconds after started.
Test2
Continued from Test 1
1. Unplug 3 pin connector CN701. CN703 remains unplugged.
2. Program oven at High power for 1 minute and press start.
a. After approximately 3 seconds, oven stops.
b. During oven operation, input current is approximately
0.4A.
INPUT AMPERE FAILURE CODE
Unplug CN701 <0.4A Oven stops in 3
seconds after started.
If both a and b check OK, the Inverter Power Supply (U) can be
determined to be OK.
5.6. Temperature thermistor
Those sensor monitors the heat produced by the heater circuit
and maintains the magnetron temperature which user had
selected. The reading across the temperature thermistor
should be 7.2 K
Ω ± 7% in an area with the 75°C temperature.
If the resistance reading is out of the range stated here, the
thermistor is detective and must be replaced.
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NN-GD376S / NN-GD366M / NN-GD356W