1 Answer

H97, H98 and H99 appears in display window a short time alter start key is pressed and no microwave oscillation with AC Ampere meter used for troubleshooting.

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 or 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.

Information source: http://www.applianceaid.com/microwave-fault-codes.php

My best suggestion, buy a new microwave.