Panasonic 1100W Service Manual - Page 23

Troubleshooting of Inverter Circuit (U) and Magnetron NEW H.V. This oven is programmed with a self diagnostics failure code system which will help for troubleshooting. H97, H98, and H99 are the provided failure codes to indicate magnetron and inverter circuit problem areas. This section explains failure codes of H97, H98, and H99. First, you must program the DPC by pressing Clock , Time , Start , Power Level . Program unit for operation. H97, H98, H99 appears in display window a short time after start key is pressed and there is no microwave oscillation. H97, H98, or H99 appears in display window Check magnetron filament continuity Open Magnetron* OK refer to componenet test procedures Check Inverter input AC voltages at OV CN702 AC 120V unplug CN702 and measure at lead wire harness side DPC board Loose relay wiring Check inverter control signal at OV CN701, pin 1 and 2 AC3V unplug CN701 and measure at lead wire harness side DPC board H.V. Inverter (U) (SEE NOTE) NOTE: After check, unplug unit to reset to normal operation mode. NOTE: DO NOT try to repair this Inverter Power Supply (U) and also DO NOT RE-ADJUST PRESET VOLUME on the board. It is very dangerous to repair or adjust without sufficient test equipment because this circuit handles very high voltage and very large current. Off alignment of inverter board operation is dangerous. Operating a misaligned Inverter circuit is dangerous due to the very high voltage and current that is produced by this board. Defective boards must be replaced with a new one. * Check magnetron filament for open or short to casing before proceeding to determine a good magnetron. Alternate way to troubleshoot oven with AC Ampere meter used H97, H98, H99 appears in display window a short time after start key is pressed and no microwave oscillation with AC Ampere meter used for troubleshooting H97, H98, or H99 appears in display window Check oven input AC amperes measure at oven plug more than 1A 0.4-0.8A DPC board Loose wiring Check magnetron filament continuity Open OK refer to component test procedures Magnetron* NOTE: If filament is opened, AC input Amperes 1 to 1.7A will flow STOP! If all the above are OK up to this point, there may be a H. V. Inverter problem (SEE NOTE) NOTE: After check, unplug unit to reset to normal operation mode. NOTE: DO NOT try to repair this Inverter Power Supply (U) and also DO NOT RE-ADJUST PRESET VOLUME on the board. It is very dangerous to repair or adjust without sufficient test equipment because this circuit handles very high voltage and very large current. Off alignment of inverter board operation is dangerous. Operating a misaligned Inverter circuit is dangerous due to the very high voltage and current that is produced by this board. Defective boards must be replaced with a new one. * Check magnetron filament for open or short to casing before proceeding to determine a good magnetron. - 22 -