Inverter Power Supply (U); Temperature Thermistor; Circuit Breaker - Panasonic NN-CS596S BPQ Service Manual

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. Press Timer pad twice.
b. Press Start pad once.
c. Press Micro Power pad once.
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
Unplug CN703 0.5 to 1A
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
Unplug CN701
If both a and b check OK, the Inverter Power Supply (U) can be
determined to be OK.
FAILURE CODE
Oven stops in 23
seconds after started.
FAILURE CODE
<0.4A Oven stops in 3
seconds after started.
5.6.

Temperature thermistor

These sensor monitors the heat produced by the heater circuit
and maintains the magnetron temperature which user had
selected. Normal room temperature 10°C to 30°C, the reading
across the temperature thermistor should be as follows.
TEMP MAGNETRON
THERMISTOR
100°C 30-60KΩ
25°C 700K-1.5MΩ
If the resistance reading is out of the range stated here, the
thermistor is detective and must be replaced.
5.7.

Circuit breaker

1. Turn the switch of circuit breaker to the "I" position and then
plug in the oven.
2. Press the "TEST" button on circuit breaker, if the switch
jump back to "O" position, you may decide the circuit
breaker functions properly.
21
STEAM HEATER OVEN
THERMISTOR THERMISTOR
10-20KΩ 10-20KΩ
100K-300KΩ 100K-300KΩ
NN-CS596S