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© 2001 Matsushita Electric Industrial Co., Ltd. All
rights reserved. Unauthorized copying and distribu-
tion is a violation of law.

Summary of Contents for NN-T221MB

Page 1: ...Order Number MOP0107026C2 Microwave Oven ...

Page 2: ...2 2001 Matsushita Electric Industrial Co Ltd All rights reserved Unauthorized copying and distribu tion is a violation of law ...

Page 3: ...rt of the high voltage circuit and becomes very hot 3 Do not attempt to repair the inverter PCB as this can be very dangerous Replace the high voltage inverter circuit as a complete unit 4 Do not adjust or tamper with the pre set volume on the inverter board It is very dangerous to adjust this pre set without proper test equipment 5 Do not operate the microwave oven when the inverter grounding pla...

Page 4: ...4 3 Control Panel ...

Page 5: ...o assist in programming the next operation will appear on the display When you are used to operating the oven you can turn the operating guide off 4 1 Operating Guide 4 2 Set Clock 4 3 Microwave Cooking 4 4 Autoweight Defrost 4 5 Delay Stand 4 6 Delay Start 4 7 Autoweight Cook Program ...

Page 6: ...6 4 8 To Set Child Safety Lock 4 9 Demonstration Mode ...

Page 7: ...7 5 Schematic Diagram ...

Page 8: ...e digital programmer circuit determines the power level and cooking time to complete the cooking and indicates the operating state in the display The table shows the correspond ing cooking times for respective weight by categories 2 When the cooking time in the display window has elapsed the oven is automatically turned off by the control signal from the digital programmer circuit NOTE After one t...

Page 9: ...rter warning Figure 1 WARNING FOR INVERTER POWER SUPPLY U GROUND ING Check the high voltage inverter power supply circuit ground ing The high voltage inverter power supply circuit board must have a proper chassis ground the inverter grounding bracket must be connected to the chassis If the inverter board is not grounded it will expose very high voltages and cause extreme DANGER Be sure that the in...

Page 10: ...6 Confirm after repair 1 After repair or replacement of parts make sure that the screws of the oven etc are neither loose nor missing Microwaves might leak if screws are not properly tight ened 2 Make sure that all electrical connections are tight before inserting the plug into the wall outlet 3 Check for microwave energy leakage Refer to proce dure for measuring microwave energy leakage CAUTION M...

Page 11: ... magnetron Figure 1 8 2 Inverter power supply U 1 Discharge the high voltage capacitors 2 Remove two screws holding the tie bar 3 Unplug the H V Lead wires from the magnetron 4 Remove the one screw holding the earth wire to the mag netron 5 Remove the connector CN701 and CN702 from the inverter PCB 6 Remove the two screws holding the inverter base to the chassis See figure 2 7 Carefully remove the...

Page 12: ...s or uneven sur faces can be avoided Removal of DPC AU and DPC DU Figure 4 8 4 Low voltage transformer and or power relays RY1 Note Be sure to ground your body to discharge any static before handling the DPC 1 Using a solder wick or a de soldering tool and a 30W sol dering iron carefully remove all solder from the terminal pins of the low voltage transformer and or power relays 2 With all of the t...

Page 13: ... hooks Care must be taken not to damage these hooks during disassembly 4 Remove the door key and spring from the door E After replacement of the defective component parts of the door reassemble and follow the instructions below for proper installation and adjustment so as to prevent exces sive microwave leakage 1 When mounting the door to the oven be sure to adjust the door parallel to the bottom ...

Page 14: ... motor 3 Remove the turntable motor by removing the two screws Note After breaking off the motor cover make sure that cut off portions are properly trimmed off or bent inside so that no sharp edges are exposed Note To secure the motor cover use a 4 x 6 screw Removing the turntable motor cover Figure 9 Removing the two scews fixing the turntable motor Figure 10 ...

Page 15: ... inverter primary termi nals 2 Connect the test probes of the ohm meter to the discon nected leads 3 Test the continuity of the short switch with the door open and the door closed using the lowest ohm scale 9 3 Magnetron Continuity checks can only indicate an open filament or a shorted magnetron To diagnose an open filament or shorted magnetron 1 Isolate the magnetron from the circuit by disconnec...

Page 16: ...till functioning 9 7 Temp Sensor Thermal Protec tor A temperature sensor is mounted on top of the oven cavity at the left side Its purpose is to automatically shut off the oven in case the cavity overheats for any reason The thermal protector will shut the oven off when the tempera ture of the cavity reaches 257 F 125 C The device is connected to the DPC ontouch control models When the thermal pro...

Page 17: ...smoothly after adjustment is completed Completely tighten the screws holding the door hook assembly to the oven assembly 3 Reconnect the short switch primary switch and second ary latch switches and check the continuity of the monitor circuit and latch switches by following the component test procedures on page 17 10 2 Measurement of microwave output The output power of the magnetron can be determ...

Page 18: ...18 11 TroubleShooting Guide ...

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