Panasonic NN-CF771S - 9 Troubleshooting Guide

9 TROUBLESHOOTING GUIDE
DANGER: HIGH VOLTAGES
1. DO NOT RE-ADJUST PRESET CONTROL on the H.V.Inverter (U). It is very dangerous to repair or adjust without proper test equipment
because this circuit generates very large current and high voltage. Operating a misaligned inverter circuit is dangerous.
2. Ensure proper grounding before troubleshooting.
3. Be careful of the high voltage circuitry, taking necessary precautions when troubleshooting.
4. Discharge high voltage remaining in the H.V.Inverter (U).
5. When checking the continuity of the switches or the H.V.Inverter, disconnect one lead wire from these parts and then check continuity with the
AC plug removed. Doing otherwise may result in a false reading or damage to your meter. When disconnecting a plastic connector from a
terminal, you must hold the plastic connector instead of the lead wire and then disconnect it, otherwise lead wire may be damaged or the
connector cannot be removed.
6. Do not touch any parts of the circuitry on the digital programmer circuit, since static electric discharge may damage this control panel. Always
touch ground while working on this panel to discharge any static charge in your body.
7. 230V AC is present on the digital programmer circuit (Terminals of power relay’s and primary circuit of Digital Programmer Circuit). When
troubleshooting, be cautious of possible electrical shock hazard.
Before troubleshooting, operate the microwave oven following the correct operating procedures in the instruction manual in order
to find the exact cause of any trouble, since operator error may be mistaken for the oven’s malfunction.
Self diagnostic display
Oven has self diagnostic function but it will not be activated in normal operation mode.
To show self diagnostic result, please take the following steps.
1. Firstly, you must program the DPC into TEST MODE (Plug-in oven → press Clock
button once → press Timer button once
→ press Start
button once → press Micro Power button once.)
2. Error code list
H** Hardware problem, oven itself has problem.
U** Usage problem such as run out of water and oven itself works well.
Error code Cause for error
H99 Inverter on/off control error
H98 Magnetron no oscillation error
H97 Inverter input error
H96 Inverter custom IC error
H95 Inverter input failure
H90 Power down controlled by Inverter thermistor
Usage problem
U65 Power down controlled by Inverter thermistor
HOT Oven is hot (It is able to show up both in test mode and cooking mode)
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NN-CF771S