Panasonic Microwave Oven Error Codes

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.

Error CodesSolutions
H99Inverter on/off control error
H98Magnetron no oscillation error
H97Inverter input error
H96Inverter custom IC error
H95Inverter input failure
H90Power down controlled by Inverter thermistor
H44Key board switch failure
H39Steam heater thermistor failure
H32Magnetron thermistor failure
H30Oven thermistor failure
H02Memory IC error (It is able to show up both in test mode and cooking mode)
H00RAM failure (It is able to show up both in test mode and cooking mode)
H20Steam heater open error
U14No water during steam cooking (It is able to show up both in test mode and cooking mode)
U40No load operation
U65Power down controlled by magnetron thermistor
HOTOven is hot (It is able to show up both in test mode and cooking mode)
F33Open temperature sensor (exhaust)
F34Short temperature sensor (exhaust) (Rare)
F44Shorted membrane switch
F01Exhaust temperature exceeds 120° C(260 F). Burning food in the oven due to overcooking
F05Memory failure. Digital programmer circuit failure
F09Oven that was designed for 50Hz electricity is attempted to operate in the 60Hz environment. If the model number of the oven in question is listed above, most likely the controller (DPU) board has failed.
F81Excessive current comsumption (upper H.V circuit)
F82Excessive current comsumption (lower H.V. circuit)
F86Shorted contacts of RY-3. Relay failure RY-3 (Relay Board). Digital programmer circuit failure.
F87Shorted contacts of RY-4
No DisplayNo voltage supply to the LV transfomer
Panasonic Microwave Oven Components Diagram
Panasonic Microwave Oven Components Diagram

Care and Cleaning of Your Microwave Oven

Inside of the oven: Wipe with a damp cloth after using. Mild detergent may be used if needed. Do not use harsh detergents or abrasives.

Oven Door: Wipe with a soft dry cloth when steam accumulates inside or around the outside of the oven door. During cooking, especially under high humidity conditions, steam is given off from the food. (Some steam will condense on cooler surfaces, such as the oven door. This is normal.) Inside surface is covered with a heat and vapor barrier film. Do not remove.

Roller Ring and oven cavity floor: Clean the bottom surface of the oven with mild detergent water or window cleaner, and dry. Roller Ring may be washed in mild soapy water or dishwasher. These areas should be kept clean to avoid excessive noise.

Control Panel: Covered with a removable protective film to prevent scratches during shipping. Small bubbles may appear under this film. (Hint – To remove film, apply masking or clear tape to an exposed corner and pull gently.) If the Control Panel becomes wet, clean it with a soft dry cloth. Do not use harsh detergents or abrasives.

Outside oven surfaces: Clean with a damp cloth. To prevent damage to the operating parts inside the oven, water should not be allowed to seep into ventilation openings.

Panasonic Microwave Oven Troubleshooting

Oven stops in 3 seconds after pressing start pad.No input AC is supplied to H.V.Inverter (U) CN702 terminals
Oven stops in 23 seconds after pressing start pad.H.V.Inverter (U) operates by the control signals from DPC but magnetron is not oscillating
Oven stops in 1 minute after pressing start pad.Oven thermistor circuit is not functions.
Oven stops in 30 seconds after pressing start pad.Steam heater thermistor circuit is not functions.
No display and no operation at all. Fuse is blown.Most probably loose connection of connectors, or door latch mechanism is not adjusted properly.
Fan motor turns on when oven is plugged in with door closed.Misadjustment or loose wiring of secondary latch switch. Defective secondary latch switch.
Fan motor turns on and turntable rotates when door is opened.Shorted primary latch switch.
Oven does not operate and return to plugged in mode as soon as start pad is pressed.Defective DPC. Check grounding connector on escutcheon base.
Loud buzzing noise can be heard.Loose fan and fan motor.
Panasonic Microwave Oven Control Panel
Panasonic Microwave Oven Control Panel

Panasonic Microwave Oven Manual PDF – Models: NN-H625/H635/H645/H665

Panasonic Microwave Oven Owner’s Manual PDF Model: NIN-SU676S

Panasonic Operating Instruction and Cook Book Microwave Oven Model Number: NN-ST671S

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