NN-S651WF, NN-S541WF - Panasonic Home Appliance Service Manual (repair manual). Page 19

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 , Micro Power.  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.

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.

Check inverter control signal at
CN701, pin 1 and 2

H97, H98, or H99 appears in display
window

Check magnetron filament continuity

Check Inverter input AC voltages at
CN702

H.V. Inverter (U)
(SEE NOTE)

Magnetron*

DPC board
Loose relay wiring

DPC board

unplug CN701 and measure at
lead wire harness side

refer to componenet test
procedures

unplug CN702 and measure
at lead wire harness side

AC3V

OK

AC 240V

Open

OV

OV

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

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

C h e c k   m a g n e t r o n   f i l a m e n t
continuity

H97, H98, or H99 appears in display
window

Check oven input AC amperes
measure at oven plug

STOP!
If all the above are
OK up to this point,
there may be a H.
V. Inverter problem
(SEE NOTE)

DPC board
Loose wiring

Magnetron*

refer to component test
procedures

more than 0.5A

OK

less than 0.4A

Open

NOTE:  If filament is opened,
AC input Amperes 0.5 to 1A
will flow

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.

- 19 -