Panasonic NN-T259CB Service Manual Download Page 1

ORDER NO. MOP9905002C2

© 1999 Matsushita Electric Industrial Co., Ltd.
All rights reserved. Unauthorized copying and
distribution is a violation of law.

Service Manual

Microwave Oven

NN-T259WB

NN-T259CB

Specifications:

Power Source:

240 V AC Single Phase, 50 Hz

Power Requirements:

Microwave: 1100W

Output: (IEC705-88)

 900W

Microwave Frequency:

2,450Mhz

Timer:

99 min. 99 sec.

Oven Cavity Size:

20L

Outside Dimensions:

458mm (W) X 315mm (D) X 299mm (H)

Inside Dimensions:

315mm (W) X 298mm (D) X 208mm (H)

Weight:

11 Kg

Inverter Power Supply

Output power:

IEC705-88 Test procedure

Specifications subject to change without notice

Summary of Contents for NN-T259CB

Page 1: ...Specifications Power Source 240 V AC Single Phase 50 Hz Power Requirements Microwave 1100W Output IEC705 88 900W Microwave Frequency 2 450Mhz Timer 99 min 99 sec Oven Cavity Size 20L Outside Dimensions 458mm W X 315mm D X 299mm H Inside Dimensions 315mm W X 298mm D X 208mm H Weight 11 Kg Inverter Power Supply Output power IEC705 88 Test procedure Specifications subject to change without notice ...

Page 2: ... energy 3 Very high voltage may remain in the circuitry even when the oven is off High voltages may remain in the capacitors on the board DO NOT 1 Do not touch the circuitry as it becomes very hot high voltage Even when replacing board extreme care should be taken to avoid possible electric shock hazards High voltage may remain in the circuit 2 Do not touch aluminium heat sink because it is very h...

Page 3: ... transformer and or power relays RY1 13 6 5 Fan Motor 13 6 6 Temp sensor thermal protector 13 6 7 Door disassembly 14 6 8 Turntable motor 14 7 COMPONENT TEST PROCEDURE 15 7 1 Primary Latch Switch Secondary Secondary Latch Switch and Power Relay B Interlocks 15 7 2 Short Switch Monitor Circuit 15 7 3 Magnetron 15 7 4 Push button key board 15 7 5 Inverter Power Supply U 16 7 6 Inverter Power supply ...

Page 4: ...ime or for standing non cooking time 7 Clock Pad Press the clock pad Using the minute and second pads set the clock 12 hr clock Press clock pad again to stop colons flashing 8 lb oz Conversion Pad 9 Weight Selection Pads 10 Stop Cancel Button Before Cooking One press clears your instructions During Cooking One press temporarily stops the cooking program Another press cancels all your instructions ...

Page 5: ... 11 25 OPERATION DISPLAY 1 Place water load in oven 2 Press High once to set High Power HIGH SET TIME 3 Set time at 5 sec by pressing 1 sec pad 5 times 4 Press Medium to set Medium Power Once Once Twice 5 Times 11 PRESS CLOCK 25 5 Times 5 SEC PRESS START HIGH SET TIME MEDIUM 5 Set for 1 minute by pressing 1min pad once 6 Press start pad 7 When 1st stage cooking has elapsed oven automatically switc...

Page 6: ...Select auto weight program CHILLED MEAL SET WEIGHT 2 Press to select grams or pounds and ounces LB OZ CHILLED MEAL SET WEIGHT 3 Enter the weight 1LB OZ PRESS START Delay Stand H 1 00 PRESS START MIN SEC 1 00 MIN SEC H1 00 Delay Stand H 1 00 CHOOSE COOKING MODE 1H 00 g lb oz 4 Press start OPERATION DISPLAY 1 Press start 3 times to display lock LOCK OPERATION DISPLAY 1 Press stop cancel 3 times Time...

Page 7: ...7 3 SCHEMATIC DIAGRAM ...

Page 8: ...e colours of leadwire connector housing MAGNETRON HIGH VOLTAGE INVERTER SYMBOL COLOUR OR ORANGE BL BLUE BR BROWN W WHITE Y YELLOW R RED GR GREY BK BLACK PRIMARY LATCH SWITCH TOP SECONDARY LATCH SWITCH BOTTOM OUTSIDE SHORT SWITCH BOTTOM INSIDE POWER RELAY B RY1 CAUTION HEAT SINK HOT LIVE VERY HIGH VOLTAGE TEMPERATURE ...

Page 9: ...termines the power level and cooking time to complete cooking and indicates the operating state in the display The table shows the corresponding cooking times for respective weight by categories 2 When cooking time in the display window has elapsed the oven turns off automatically by the controlled signal from the digital programmer circuit NOTE After one touch menu and auto reheat cooking fan mot...

Page 10: ...ounding bracket to the chassis ground otherwise this H V Inverter circuit board will expose very high voltage and cause extreme DANGER Be sure to have proper grounding by the grounding plate and screws NEW H V HIGH VOLTAGE REMAINS IN HIGH VOLTAGE CAPACITORS DANGER OF HIGH VOLTAGE AND HIGH TEMPERATURE HOT LIVE OF HEAT SINK HEAT SINK CHOKE COIL SAND BAR RESISTOR CUSTOM I C CN 701 CURRENT TRANSFORMER...

Page 11: ...into the wall outlet 3 Check for microwave energy leakage Refer to procedure for measuring microwave energy leakage 5 7 Sharp edges WARNING When the 10A 250V fuse is blown due to the operation of short switch you must replace Primary latch switch and short switch Also replace power relay 1 RY1 when the continuity check reads shorted contacts 1 2 CAUTION MICROWAVE RADIATION DO NOT BECOME EXPOSED TO...

Page 12: ...t 4 Remove 1 screw and remove the inverter PCB plus support base from the oven 5 Remove 1 screw to disconnect earth wire to magnetron 6 Remove 4 screws holding inverter power supply board to the Inverter bracket 7 Replace with replacement PCB and follow the steps in reverse CAUTIONS WHILE REPLACING INVERTER POWER SUPPLY U 1 Make sure to leave grounding plate in its place 2 Make sure to securely ti...

Page 13: ...the DPC 1 Using solder wick or a desoldering tool and 30W soldering iron carefully remove all solder from the terminal pins of the low voltage transformer and or power relays NOTE Do not use a soldering iron or desoldering tool of more than 30 watts on DPC contacts 2 With all the terminal pins cleaned and separated from DPC contacts remove the defective transformer power relays and install new tra...

Page 14: ...r hinge in the direction necessary for proper alignment 2 Adjust so that the door has no play between the inner door surface and oven front surface If the door assembly is not mounted properly microwave power may leak from the clearance between the door and oven 3 Perform the microwave leakage test 6 8 Turntable motor 1 Remove the motor cover by breaking off at the 8 spots indicated by arrows See ...

Page 15: ...n 1 Isolate magnetron from the circuit by disconnecting the leads 2 A continuity check across magnetron filament terminals should indicate one ohm or less 3 A continuity check between each filament terminal and magnetron case should read open 7 4 Push button key board Check continuity between switch terminals by tapping an appropriate pad on the key board The contacts assignment of the respective ...

Page 16: ...f the cavity reaches 257 F 125 C The device is connected to the DPC on touch control models When the thermal protector exceeds its temperature it will turn off the power to oven cavity and display will go to reset mode The cooking program can be reset after cool down THERMISTOR RESISTANCE VALUE 30K 120K at 10 C 30 C 50 F 86 F HEAT SINK CHOKE COIL SAND BAR CUSTOM I C PHOTO COUPLER CN 701 CURRENT TR...

Page 17: ...n using the simple method outlined below Necessary Equipment 1 litre beaker Glass thermometer Wrist watch or stopwatch NOTE Check the line voltage under load Low voltage will lower the magnetron output Take the temperature readings and heating time as accurate as possible 1 Fill the beaker with exactly one litre of tap water Stir the water using the thermometer and record the beaker s temperature ...

Page 18: ...o operation at all Fuse is blown 1 Shorted lead wire harness 2 Defective primary latch switch NOTE 1 3 Defective short switch NOTE 1 4 Defective Inverter power supply U Refer to component test procedure Page 15 Check adjustment of primary secondary latch switch and short switch including door NOTE 1 All of these switches must be replaced at the same time Refer to adjustment instructions Check cont...

Page 19: ...TIONS NEW H V CLOCK DELAY STAND START HIGH POWER DISPLAY 4L1BPQ H97 H98 appears in the Check magnetron filament OK Check Inverter input AC AC 240V Check Inverter control signal Approx AC 3V refer to component unplug CN702 and measure unplug CN701 and measure Open 0V 0V DANGER Magnetron DPC board Power Relay Loose relay wiring Latch switch DPC board H V Inverter U NOTE DO NOT try to REPAIR this Inv...

Page 20: ...refer to component less than 0 4A Open DANGER Magnetron DPC board Power Delay Loose wiring Latch switch DO NOT try to REPAIR this Inverter Power Supply U display window pares measure at oven plug continuity test procedures HIGH VOLTAGE 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 handles very hi...

Page 21: ...ven though the program has been set and the start pad is tapped 1 IC 1 pin 11 voltage while operation Abnormal IC 1 Normal 5V Step 2 2 Short circuit between pin 6 and pin 16 of IC 2 Still not turn on RY 2 RY 2 turns on IC 220 No microwave oscillation at any power setting 1 IC 1 pin 7 and 72 voltages while oper ation at high power Abnormal IC 1 Normal 7 5V 72 5V Step 2 2 Q220 transistor Abnormal Q2...

Page 22: ...22 10 EXPLODED VIEW AND PARTS LIST 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 ...

Page 23: ...CE 1 14 E400A4760JP FAN MOTOR 1 15 E42094L00GS LOWER ORIFICE 1 16 E4008 1640 FANBLADE 1 17 E40314L00GS AIR GUIDE C 1 18 XTWANE4 12B SCREWS 4 FOR MAGNETRON 19 2M236 M42E2 MAGNETRON 1 20 E030E4L00GS H V LEADWIRE 1 21 E610T6700BP OVEN LAMP 1 22 E20994L00GS TIE BAR 1 23 E40254L00GS AIR GUIDE A 1 24 E66014L00GS INVERTER EARTH BRACKET 1 25 E65854L00GS INVERTER SUPPORT BRACKET 1 26 E606Y4L10GP INVERTER 1...

Page 24: ...6 D7 Ref No Part No Part Name Description Pcs Set Remarks D1 E302A4L10HBP DOOR A SCREEN B ASSEMBLY 1 NN T259WB D1 E302A4L10BP DOOR A SCREEN B ASSEMBLY 1 NN T259CB D2 E30214000AP DOOR KEY SPRING 1 D3 E30184L00GS DOOR KEY A 1 D4 E302K4L00GS DOOR E AND SCREEN A UNIT 1 D5 E31454L00GS SCREEN A 1 D6 E30854L00GS DOOR C 1 D7 E30064L00GS UPPER HINGE 1 ...

Page 25: ...ENING BUTTON 1 NN T259CB E2 E80378AOAG DOOR BUTTON SPRING 1 E3 E80344L10HBP ESCUTCHEON BASE 1 NN T259WB E3 E80344L10BP ESCUTCHEON BASE 1 NN T259CB E4 E81274L10BP ESCUTCHEON BACK PLATE 1 E5 E603L4L10BP DPC AU 1 E6 E66164L00GS RIBBON CABLE 1 E7 E82564L10BP DOOR OPENING LEVER 1 E8 E603Y4L10BP DPC DU 1 E9 E83264L10BP DISPLAY SHEET 1 E10 E00074L10BP NAME PLATE 1 E11 E83374L10HBP ESCUTCHEON SHEET 1 NN T...

Page 26: ... Pcs Set Remarks P1 E290D4060AP ROLLER RING 1 P2 E202K4080BP ROLLER BEAD ASSEMBLY 3 Note 1 P3 E06014L00BP GLASS TRAY 1 P4 E00034L20BP INSTRUCTION BOOK 1 P5 E01695750BP SERVICE CENTER LIST 1 P6 E01084L00GS TRAY PACKING 1 P7 E01054L00BP LOWER FILLER 1 P8 E01024L10HBP CARTON BOX 1 NN T259WB P8 E01024L10BP CARTON BOX 1 NN T259CB P9 E01078990BP DOOR SHEET 1 P10 AEE01066Q0BP VINYL COVER 1 P11 E01927550G...

Page 27: ...t No Description Qty Remarks R1 ERG1SJ753P RESISTOR 1 75KΩ 1W C1 C2 AECQJ5225KX1 CAPACITOR 2 2 2µf C3 C4 ECKMNA472ME CAPACITOR 2 4700pF 250V AC L1 E621A4J00XN FILTER COIL 1 2 4mH GND E03594080BP EARTH WIRE 1 F1 E62316010BP FUSE HOLDER 1 10A 250V AC ...

Page 28: ...28 15 DIGITAL PROGRAMMER CIRCUIT ...

Page 29: ...29 ...

Page 30: ...RJ3GSYJ683V CHIP RESISTOR 9 68KΩ Ref No Part No Description Qty Remarks CN5 AEEM19FEBVKN 19 PIN CONNECTOR 1 CN1 AEEMMD05507W 7 PIN CONNECTOR 1 RY1 AEGG5G1A12 RELAY 2 12V RY2 RY3 AEBGG5N1A12 RELAY 2 12V D1 ERZV10D511CS VARISTOR 1 D2 D3 ERZV10D112C1 VARISTOR 2 1C25 AEICP25011HL PHOTOCOUPLER 1 D26 AESTS1WBA60B DIODE BRIDGE 1 BZ310 EFBAH20C001 BUZZER 1 2KHz IC10 ETXMJ197X1BG SWITCH POWER SUPPLY 1 CN3 ...

Page 31: ...31 NOTES ...

Page 32: ...32 NOTES SM K PEN S 4L10BP Printed in the UK ...

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