Sharp microwave troubleshooting

Sharp is a Japanese Corporation for the production of household appliances and consumer electronics. It was founded on the 15th of September, 1912. The Corporation is a world-renowned developer of innovative products and new technologies, which covers all its articles including microwaves. Below you will find a very simple and useful troubleshooting table. It should help in revealing errors and repairs.

SHARP R-254M microwave troubleshooting

PROBLEMPOSSIBLE CAUSE
Draught circulates around the door.When oven is working, air circulates within the cavity. The door does not form an airtight seal so air may escape from the door.
Condensation forms in the oven, and may drip from the door.The oven cavity will normally be colder than the food being cooked, and so steam produced when cooking will condense on the colder surface. The amount of steam produced depends on the water content of the food being cooked. Some foods, such as potatoes have a high moisture content. Condensation trapped in the door glass should clear after a few hours.
Flashing or arcing from within the cavity when cooking.Arcing will occur when a metallic object comes into dose proximity to the oven cavity during cooking. This may possibly roughen the surface of the cavity, but would not otherwise damage the oven.
Arcing potatoes.Ensure all "eyes" are removed and the potatoes have been pierced, stand directly onto the turntable or in a heat resistant flan dish or similar.
After setting the time, the oven does not start.Check the door is closed properly.
Oven cooks too slowly.Ensure correct power level has been selected.
Oven makes a noise.The microwave energy pulses ON/OFF during cooking/defrosting.
Outer cabinet is hot.The cabinet may become hot to the touch - keep children away.

SHARP R-259 microwave troubleshooting

QUERYANSWER
Draught circulates around the door.When the oven is working, air circulates within the cavity. The door does not form an airtight seal so air may escape from the door.
Condensation forms in the oven, and may drip from the door.The oven cavity will normally be colder than the food being cooked, and so steam produced when cooking will condense on the colder surface. The amount of steam produced depends on the water content of the food being cooked. Some foods, such as potatoes have a high moisture content. Condensation trapped in the door glass should clear after a few hours.
Flashing or arcing from within the cavity when cooking.Arcing will occur when a metallic object comes into close proximity to the oven cavity during cooking. This may possibly roughen the surface of the cavity, but would not otherwise damage the oven.
Arcing potatoes.Ensure all “eyes” are removed and the potatoes have been pierced, place directly onto the turntable or in a heat resistant flan dish or similar.
The display is lit but the control panel will not work when pressed.Check the door is closed properly.
Oven cooks too slowly.Ensure correct power level has been selected.
Oven makes a noise.The microwave energy pulses ON and OFF during cooking/defrosting.
Outer cabinet is hot.The cabinet may become warm to the touch - keep children away.

Sharp R-820BK microwave troubleshooting

SYMPTOMCAUSECORRECTIONS
Oven is dead. Fuse is OK. No display and no operation at all.1. Open or loose lead wire harnessCheck fan motor when thermal cutout is defective.
2. Open thermal cutout (Cavity)
3. Open low voltage transformer
4. Defective DPC
No display and no operation at all. Fuse is blown.1. Shorted lead wire harnessCheck adjustment of primary, secondary latch switch and shon switch including door.
2. Defective primary latch switdh (NOTE 1)
3. Defective short switch (NOTE 1)
4. Defective Inverter Power Supply (U) (Page 18)
Oven does not accept key input(Program)1. Key input is not insequenceRefer to operation procedure. Refer to DPC troubleshooting.
2. Open or loose connection of membrane key pad to DPC (Flat cable)
3. Shorted or open membrane key board
4. Defective DPC
Fan motor turn on when oven is plugged in with door closed.1. Misadjustment or loose wiring of secondary latch switchAdjust door and latch switches.
2. Defective secondary latch switch
Timer starts count down but no microwave oscillation. (No heat while oven lamp and fan motor turn on)1. Off-alignment of latch switchesAdjust door and latch switches. Check high voltage component according to component test procedure and replace if it is defective. Refer to DPC troubleshooting Adjust door and latch switches.
2. Open or loose connection of high voltage drcuit especially magnetron filament circuit
NOTE: Large contact resistance will bring lower magnetron filament voltage and causing magnetron to lower output and/or be intermittent.
3. Defective high voltage component HV Inverter Power Supply (u) Magnetron
4. Open or loose wiring of power relay B (RY-1)
5. Defective primary latch switch
6. Defective DPC or power relay B (RY-1)
Oven can program but timer does not start countdown.1. Open or loose wiring of secondary latch switch
2. Off-alignment of secondary latch switch
3. Defective secondary latch switch
Microwave output is low. Oven takes longer time to cook food.1. Decrease in power source voltageConsult electrician
2. Open or loose wiring of magnetron filament circuit.(lntermittent oscillation)
3. Aging change of magnetron
Fan motor turns on and turntable rotates when door is opened.1. Shorted primary latch switch
Oven does not operate and return to plugged in mode as soon as start pad is pressed.1. Defective DPCCheck tighten screws on escutcheon base bracket. D.P.C. board.
Loud buzzing noise can be heard.1. Loose fan and fan motor
Turntable motor does not rotate.1. Open or loose wiring of turntable motor
2. Defective turntable motor
Oven stops operation during cooking.1. Open or loose wiring of primary and secondary latch switch 2.0peration of thermal cutoutAdjust door and latch switches.
Oven returns to plugged in mode after 10 seconds elapses on the Auto sensor cooking mode.1 .Open or loose wiring of sensor terminal from DPC
2.Open steam sensor 3.Defective DPC

Sharp R-963M microwave troubleshooting

PROBLEMPOSSIBLE CAUSE/SOLUTION
Digital display does not light-up.Check the oven is plugged in. Plug in another appliance to check the mains supply is feeding the socket. Replace the fuse.
Draught circulates around the door.When the oven is working, air circulates within the cavity. The door does not form an airtight seal so air may escape from the door.
Condensation forms in the oven, and may drip from the door.The oven cavity will normally be colder than the food being cooked, and so steam produced when cooking will condense on the colder surface. The amount of steam produced depends on the water content of the food being cooked. Some foods, such as potatoes have a high moisture content. Condensation trapped in the door glass should clear after a few hours.
Flashing or arcing from within the cavity when cooking.Arcing will occur when a metallic object comes into close proximity to the oven cavity during cooking. This may remove some of the paint and possibly roughen the surface of the cavity, but would not otherwise damage the oven. Bare metal should be touched up with acrylic paint to prevent the formation of rust.
Arcing potatoes.Ensure all "eyes" are removed and stand directly onto the turntable or in a heat resistant flan dish or similar.
Control panel buttons do not operate.Check the door is closed properly.
Oven cooks too slowly.Ensure correct mode and power level has been selected.
Oven makes a noise.The cooling fan generates noise. The microwave energy pulses ON/OFF during cooking/defrosting.
If the display shows different messages from ENERGY SAVE MODE when you plug the oven in and open the door. If you are unable to programme your oven or the microwave energy does not pulse on and off during use.Your oven may be set in demo mode. Follow the steps below to cancel the demo mode.
1. Press the STOP/CLEAR key for ten seconds until you hear the beep twice.
2. Press the STOP/CLEAR key ten times within ten seconds.
3. The oven display will show "DEMO OFF".