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

DPC board

CN702

 

 

 

 

 

Loose relay wiring

AC 120V

unplug CN702 and measure

 

 

 

 

 

at lead wire harness side

 

 

 

 

 

 

OV

 

 

 

 

 

Check inverter control signal at

 

DPC board

CN701, pin 1 and 2

 

 

 

 

 

 

 

 

 

AC3V

unplug CN701 and measure at

 

 

 

 

 

lead wire harness side

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

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 han- dles very high voltage and very large current. Off alignment of inverter board operation is dangerous. Operating a misaligned Inverter cir- cuit 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

0.4-0.8A

measure at oven plug

 

 

 

more than 1A

 

 

 

 

Open

 

 

 

Check

magnetron filament

continuity

 

OK

 

refer to component test

 

 

procedures

 

 

 

 

 

DPC board

Loose wiring

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: 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 han- dles very high voltage and very large current. Off alignment of inverter board operation is dangerous. Operating a misaligned Inverter cir- cuit 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.

NOTE: After check, unplug unit to reset to normal operation mode.

- 22 -

Page 23
Image 23
Panasonic NN-L530BF, NN-S560BF, NN-S560WF service manual Troubleshooting of Inverter Circuit U and Magnetron NEW H.V