Troubleshooting Guide - Panasonic NN-CT577SEPG Service Manual

12 Troubleshooting Guide

1. Do not try to repair the H.V. Inverter power supply. Replace the inverter circuit board as a complete unit.
2. Do not adjust the preset volume on the Inverter. It is very dangerous to repair or adjust without special test
equiptment, the inverter handles very high voltage and current.
3. Do not attempt to measure the voltages in the microwave oven high voltage circuit.
4. Always discharge the high voltage capacitors on the inverter circuit board before troubleshooting.
5. When checking the continuity of the components on the H.V. Inverter circuit, unsolder and remove one leg of
the component from circuit board. Checking the continuity of these components when both legs are soldered
into the board may result in a false reading or damage to your meter.
6. When disconnecting a plastic connector from a terminal, you must hold the plastic connector and not the lead
wire, otherwise the lead wire may become open circuit.
7. Do not touch components on the digital programmer circuit, this circuit is sensitive to static electricity.
8. When working with the digital programmer board ensure your body is connected to ground to discharge any
static charge.
9. 240 VAC is present on the digital programmer circuit. (Terminals of the power relays and the primary circuit of
the low voltage transformer). When troubleshooting, be cautious of possible electric shock.
To ensure the complaint is not due to operator error, check the operation of the oven by following the procedures
explained in the operating instruction book.
Self diagnostic display
The oven has self diagnostic function which can be activated as follows:
To show self diagnostic result, please take the following steps.
1. Firstly, you must program the DPC into TEST MODE (Plug-in oven - press Timer pad twice - press Start pad
once -press Timer pad once - press Micro Power pad once.)
2. Keep pressing Timer pad for more than 2 seconds until buzzer beeps.
3. Press Start pad twice, oven will show error code.
NOTE:
1. The last 3 consecutive errors are stored in memory.
2. Press Start pad again, the previously stored error code will be displayed.
3. If the oven is ok, it will show "000" and blink.
4. Error code list
H** Hardware problem, oven itself has problem.
U** Usage problem such as no load operation and oven itself works well.
Error code
H99
H98
H97
H96
H95
H90
H44
H32
H30
U40
U65
Caution
Cause for error
Inverter on/off control error
Magnetron no oscillation error
Inverter input error
Inverter custom IC error
Inverter input failure
Power down controlled by Inverter thermistor
Key board switch failure
Magnetron thermistor failure
Oven thermistor failure
Usage problem
No load operation
Power down controlled by magnetron thermistor
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