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Unlike many other appliances, the microwave oven is a high
voltage, high current device. It is free from danger in ordinary
use, though extreme care should be taken during repair.

CAUTION

Servicemen should remove their watches and rings
whenever working close to or replacing the magnetron.

3.1. Check the grounding

Do not operate on a two wire extension cord. The microwave
oven is designed to be grounded when used. It is imperative,
therefore, to ensure the appliance is properly grounded before
beginning repair work.

3.2. Inverter warnings

WARNING HIGH VOLTAGE AND HIGHTEMPERATURE

(HOT/LIVE) OF THE INVERTERPOWER SUPPLY (U)

The High Voltage Inverter Power Supply generates very
high voltage and current for the magnetron tube. Though it
is free from danger in ordinary use, extreme care should be
taken during repair.
The aluminum heat sink is also energized with high voltage
(HOT), do not touch when the AC input terminals are
energized. The power device Collector is directly connected
to the aluminum heat sink.
The aluminum heat sink may be HOT due to heat energy,
therefore, extreme care should be taken during servicing.

H.V. Inverter warning

WARNING FOR INVERTER POWER SUPPLY (U)

GROUNDING

Check the High Voltage Inverter Power Supply circuit
grounding. The high voltage inverter power supply circuit
board must have a proper chassis ground. The inverter
grounding plate must be connected to the chassis. If the
inverter board is not grounded it will expose the user to very
high voltages and cause extreme DANGER! Be sure that
the inverter circuit is properly grounded via the inverter
grounding plate.

Grounding of the inverter circuit board

WARNING

DISCHARGE

THE

HIGH

VOLATGE

CAPACITORS

For about 30 seconds after the oven is turned off, an
electric charge remains in the high voltage capacitors of the
Inverter Power Supply circuit board.
When replacing or checking parts, remove the power plug
from the outlet and short the inverter output terminal of the
magnetron filament terminals to the chassis ground with an
insulated handle screwdriver to discharge. Please be sure
to contact the chassis ground side first and then short to the
output terminal.

3 CAUTIONS TO BE OBSERVED WHEN

TROUBLESHOOTING

9

NN-SD681S / NN-SN671S / NN-SN661S / NN-SA661S / NN-SA651S / NN-SN651B / NN-SN651W / NN-SA631B / NN-SA631W

Summary of Contents for NN-SA631B

Page 1: ...Panasonic Home Appliances Microwave Oven Shanghai Co Ltd 2011 NN SD681S NN SN671S NN SN661S NN SA661S NN SA651S NN SN651B NN SN651W NN SA631B NN SA631W APH USA Microwave Oven ORDER NO PHAMOS1105001CE E1 ...

Page 2: ...2 NN SD681S NN SN671S NN SN661S NN SA661S NN SA651S NN SN651B NN SN651W NN SA631B NN SA631W ...

Page 3: ...3 NN SD681S NN SN671S NN SN661S NN SA661S NN SA651S NN SN651B NN SN651W NN SA631B NN SA631W ...

Page 4: ...ard membrane Membrane switch assembly 16 5 5 Inverter power supply U 17 6 MEASUREMENTS AND ADJUSTMENTS 18 6 1 Adjustment of primary interlock switch secondary interlock switch and monitor switch 18 6 2 Measurement of microwave output 18 7 PROCEDURE FOR MEASURING MICROWAVE ENERGY LEAKAGE 19 7 1 Equipment 19 7 2 Procedure for measuring radiation leakage 19 7 3 Record keeping and notification after m...

Page 5: ...1 SCHEMATIC DIAGRAM 1 1 NN SD681S 5 NN SD681S NN SN671S NN SN661S NN SA661S NN SA651S NN SN651B NN SN651W NN SA631B NN SA631W ...

Page 6: ...1 2 EXCEPT NN SD681S 6 NN SD681S NN SN671S NN SN661S NN SA661S NN SA651S NN SN651B NN SN651W NN SA631B NN SA631W ...

Page 7: ...e operating conditions and output necessary to control PWM signal to the Inverter Power Supply for control of the output power 2 3 Inverter defrost When the Auto Control feature is selected and the Start pad is tapped 1 The digital programer circuit determines the power level and cooking time to complete cooking and indicates the operating state in the display window Table shows the corresponding ...

Page 8: ...he Auto Sensor Reheat process is similar as Auto Sensor Cooking process Balance of cooking time T2 time The balance of cooking time which is called T2 time can be calculated by the following formula T2 time in sec T1 time X K factor 150 NOTE Remember the T1 time starts after the 10 second period The coefficient K is programmed into the microprocessor memory and they are listed in the following tab...

Page 9: ... to heat energy therefore extreme care should be taken during servicing H V Inverter warning WARNING FOR INVERTER POWER SUPPLY U GROUNDING Check the High Voltage Inverter Power Supply circuit grounding The high voltage inverter power supply circuit board must have a proper chassis ground The inverter grounding plate must be connected to the chassis If the inverter board is not grounded it will exp...

Page 10: ...etal object through the lamp holes on the cavity or any holes or gaps because such objects may work as an antenna and cause microwave leakage 3 6 Verification after repair 1 After repair or replacement of parts make sure that the screws of the oven etc are neither loosen or missing Microwave energy might leak if screws are not properly tightened 2 Make sure that all electrical connections are tigh...

Page 11: ...1 Disconnect connector CN701 on H V Inverter board 2 Remove 1 screw holding escutcheon base and slide the escutcheon base upward slightly 3 Remove all screws holding D P C board on escutcheon base 4 Separate D P C board from tabs on the escutcheon base and remove D P C board To replace membrane key board 5 Use tools such as kinfe etc to lift the edge of escutcheon sheet and peel off escutcheon she...

Page 12: ...solder all terminal contacts carefully 4 4 Fan motor 1 Disconnect 2 lead wires from fan motor terminals 2 Remove 2 screws at location on oven attaching orifice assembly 3 Remove orifice assembly from oven assembly 4 Remove fan blade from the fan motor shaft by pulling it straight out 5 Remove 2 screws holding fan motor to orifice 4 5 Door assembly 1 Support the door remove 3 screws holding hinge A...

Page 13: ...t the door onto the hinge NOTE Door alignment is crucial If door is misaligned apply pressure until alignment is achieved NOTE Adjust so that the upper portion of the door will touch firmly to the oven cavity front plate without pushing the door If the door assembly is not mounted properly microwave power may leak from the clearance between the door and oven 9 Tighten 2 mounting screws Be sure the...

Page 14: ...w turntable motor and reconnecting the 2 lead wires reinstall the motor cover by rotating it around 180 tucking the 2 tabs under the base in the 2 provided slots then screw the single tab to the base using a 4mm 6mm screw 4 7 Steam sensor Only for sensor models 1 Disconnect connector CN2 from digital programmer circuit board 2 Disengage catch hooks on sensor cover C from orifice 3 Remove steam sen...

Page 15: ...ove the H V lead wire from magnetron terminals 3 Disconnect 2 connectors from CN701 CN702 on H V Inverter U 4 Remove 1 screw holding grounding plate to the base 5 Press 1 encircled locking tab and then slide 4 locking tabs of Inverter bracket at the bottom of the base in direction of arrows 6 Remove 1 screw holding H V Inverter to Inverter bracket 7 Remove 1 screw holding grounding plate to H V In...

Page 16: ... wires from Inverter Power Supply U primary terminals 2 Connect test probes of ohm meter to the disconnected leads that were connected to Inverter Power Supply U 3 Test the continuity of Monitor Switch with door opened and closed positions using lowest scale of the ohm meter Normal continuity readings should be as follows Door Opened Door Closed 0Ω Close Ω Open 5 3 Magnetron Continuity checks can ...

Page 17: ...tops operating b During oven operation the input current is approximately 0 5 to 1A If both a and b are OK proceed to test 2 INPUT CURRENT FAILURE CODE Unplug CN703 0 5 to 1A Oven stops in 23 seconds after started Test 2 Continued from Test 1 1 Unplug the oven s AC power supply cord from outlet 2 Unplug 3 pin connector CN701 CN703 remains unplugged 3 Plug in the oven s AC power supply cord into ou...

Page 18: ...ng the component test procedures 6 2 Measurement of microwave output The output power of the magnetron can be determined by performing IEC standard test procedures However due to the complexity of IEC test procedures it is recommended to test the magnetron using the simple method outlined below Necessary Equipment 1 liter beaker Glass thermometer Wrist watch or stopwatch NOTE Check the line voltag...

Page 19: ...pplied with the probe 4 Tap the Start pad or set the timer and with the magnetron oscillating measure the leakage by holding the probe perpendicular to the surface being measured 7 2 1 Measurement with the outer panel removed Whenever you replace the magnetron measure for radiation leakage before the outer panel is installed and after all necessary components are replaced or adjusted Special care ...

Page 20: ...7 4 At least once a year have the radiation monitor checked for calibration by its manufacturer 20 NN SD681S NN SN671S NN SN661S NN SA661S NN SA651S NN SN651B NN SN651W NN SA631B NN SA631W ...

Page 21: ...y be mistaken for the oven s malfunction H97 H98 error code display If 3 times H97 or 2 times H98 exist microwave oven can not be used any more even if the defective parts already be replaced un plug and plug in again How to reset for the service Please take the following steps 1 Plug in oven 2 Press Stop Reset pad button once 3 Open the door 4 Keep pressing Start pad button for more than 2 second...

Page 22: ...t magnetron is not oscillating 1 Magnetron 2 Loose lead wire connector CN703 3 H V Inverter U Oven stops in 10 seconds after pressing Start pad Auto sensor cooking Steam sensor circuit is not functioning 1 Steam sensor 2 DPC 3 Open or loose wiring of sensor terminal from connector CN2 on DPC 2 No display and no operation at all Fuse is blown Most probably loose connection of connectors or door lat...

Page 23: ... magnetron filament circuit NOTE Large contact resistance will cause lower magnetron filament voltage and cause magnetron to have lower output and or be intermittent 3 Defective high voltage component H V Inverter Power Supply U Magnetron Check high voltage component according to component test procedure and replace if it is defective 4 Open or loose wiring of power relay RY1 5 Defective primary i...

Page 24: ...s Timer pad once press Start pad once press Power Level pad once For NN SD681S model press Timer Clock button twice press Start button once press Power Level button once Program unit for operation H95 H97 H98 H99 appears in display window a short time after Start pad is pressed and there is no microwave oscillation Alternate way to troubleshoot oven with AC Ampere meter used H95 H97 H98 H99 appear...

Page 25: ...Q220 and or Q221 Q222 Q225 Normal 0 7V Step3 3 Short circuit between collector of Q220 and emitter of Q225 Still not turn on RY1 RY1 turns on Q220 and or Q221 Q222 Q225 Dark or unclear display 1 Replace display and check operation Normal Display Abnormal IC1 Missing or lighting of unnecessary segment 1 Replace IC1 and check operation Normal IC1 Abnormal Display H95 H97 H98 appears in window and ov...

Page 26: ...222 Q225 Normal 0 7V Step3 3 Short circuit between collector of Q220 and emitter of Q225 Still not turn on RY1 RY1 turns on Q220 and or Q221 Q222 Q225 Dark or unclear display 1 Replace display and check operation Normal Display Abnormal IC1 Missing or lighting of unnecessary segment 1 Replace IC1 and check operation Normal IC1 Abnormal Display H95 H97 H98 appears in window and oven stops operation...

Page 27: ...tween Inverter and magnetron terminal 2 Between 1 0A and 2 0A Check continuity of D702 in Inverter PCB 1 D702 shorted Replace H V Inverter F606Y8X00AP 2 D702 is OK Replace magnetron Shut off in 3 seconds after Start 1 Less than 0 5A Check open circuit Latch Switch DPC Power Relay and CN701 Replace defective component s or correct switch cables and connectors 8 6 H V INVERTER BOARD MAIN PARTS LIST ...

Page 28: ...8 7 How to check the semiconductors using an OHM meter 28 NN SD681S NN SN671S NN SN661S NN SA661S NN SA651S NN SN651B NN SN651W NN SA631B NN SA631W ...

Page 29: ...9 EXPLODED VIEW AND PARTS LIST 9 1 EXPLODED VIEW 29 NN SD681S NN SN671S NN SN661S NN SA661S NN SA651S NN SN651B NN SN651W NN SA631B NN SA631W ...

Page 30: ...40259Y00AP AIR GUIDE A 1 20 F41449Y00AP ORIFICE 1 21 J607S4T00AP STEAM SENSOR 1 SD681S SN671S SN661S SN651B SN651W 22 F64499Y00AP SENSOR COVER A 1 SD681S SN671S SN661S SN651B SN651W 24 F64508660AP SENSOR COVER B 1 SD681S SN671S SN661S SN651B SN651W 25 F65439Y00AP SENSOR COVER C 1 SD681S SN671S SN661S SN651B SN651W 26 F61425U30XN MICRO SWITCH 1 PRIMARY INTERLOCK SWITCH 27 F61415U30XN MICRO SWITCH 1...

Page 31: ...81S E6 F82569Y00AP DOOR OPENING LEVER 1 E7 F80375K00AP COOK BUTTON SPRING 1 E8 F803G9M60SBP POP OUT DIAL U 1 SD681S E9 F80189Y40AP DIAL SUPPORT 1 SD681S E10 F82989Y40SAP BUTTON 1 SD681S E11 F82989Y90SAP BUTTON B 1 SD681S E13 F66167D00AP FLAT CABLE 1 SD681S E14 F81279Y40AP BACK PANEL 1 SD681S E15 F00079Y40SAP NAME PLATE 1 SD681S E16 F33169Y40AP GROUNDING METAL 1 SD681S 31 NN SD681S NN SN671S NN SN6...

Page 32: ...SA661S SA651S E25 F630Y9Y80SAP MEMBRANE SWITCH U 1 SN671S E25 F630Y9Y30BAP MEMBRANE SWITCH U 1 SN661S E25 F630Y9Y20BAP MEMBRANE SWITCH U 1 SA661S E25 F630YBD20BAP MEMBRANE SWITCH U 1 SA651S E26 F82569Y00AP DOOR OPENING LEVER 1 E27 F80375K00AP COOK BUTTON SPRING 1 E28 F81279Y20AP BACK PANEL 1 SN671S SN661S SA661S SA651S E29 F66139Y20AP BACKSTOP 1 SN671S SN661S SA661S SA651S E35 F00079Y80SAP NAME PL...

Page 33: ...30Y9Y00BAP MEMBRANE SWITCH U 1 SN651B E45 F630Y9Y00HAP MEMBRANE SWITCH U 1 SN651W E45 F630Y9Y10BAP MEMBRANE SWITCH U 1 SA631B E45 F630Y9Y10HAP MEMBRANE SWITCH U 1 SA631W E46 F82569Y00AP DOOR OPENING LEVER 1 E47 F80375K00AP COOK BUTTON SPRING 1 E48 F81279Y00AP BACK PANEL 1 SN651B SN651W SA631B SA631W E49 F66139Y20AP BACKSTOP 1 SN651B SN651W SA631B SA631W E55 F00079Y00BAP NAME PLATE 1 SN651B E55 F00...

Page 34: ...S SA661S SA651S D2 F302A9Y10BAP DOOR A U 1 SN651B SA631B D2 F302A9Y10HCP DOOR A U 1 SN651W D2 F302A9Y10HAP DOOR A U 1 SA631W D3 F302K9Y00AP DOOR E U 1 D4 F30215G10XN DOOR KEY SPRING 1 D5 F30859Y00AP DOOR C 1 D6 F31459Y00AP DOOR SCREEN A 1 D8 F02459660AP DHHS LABEL 1 D10 F66629Y40AP GROUNDING METAL 1 SD681S 34 NN SD681S NN SN671S NN SN661S NN SA661S NN SA651S NN SN651B NN SN651W NN SA631B NN SA631W...

Page 35: ...t No Part Name Description Pcs Set Remarks W1 F030A9Y00AP LEAD WIRE HARNESS 1 INCLUDING MAGNETRON THERMISTOR W2 F030E9Y00AP H V LEAD WIRE 1 35 NN SD681S NN SN671S NN SN661S NN SA661S NN SA651S NN SN651B NN SN651W NN SA631B NN SA631W ...

Page 36: ...SAP PACKING CASE PAPER 1 SN661S P2 F01029Y20SAP PACKING CASE PAPER 1 SA661S P2 F0102BD20SAP PACKING CASE PAPER 1 SA651S P2 F01029Y00BAP PACKING CASE PAPER 1 SN651B P2 F01029Y00HAP PACKING CASE PAPER 1 SN651W P2 F01029Y10BAP PACKING CASE PAPER 1 SA631B P2 F01029Y10HAP PACKING CASE PAPER 1 SA631W P3 F01049Y00AP UPPER FILLER 1 P4 F01059Y00AP LOWER FILLER 1 P5 F01068100XN P E BAG 1 P6 F01078J00XN DOOR...

Page 37: ...10 DIGITAL PROGRAMMER CIRCUIT 10 1 SCHEMATIC DIAGRAM NN SD681S 37 NN SD681S NN SN671S NN SN661S NN SA661S NN SA651S NN SN651B NN SN651W NN SA631B NN SA631W ...

Page 38: ...38 NN SD681S NN SN671S NN SN661S NN SA661S NN SA651S NN SN651B NN SN651W NN SA631B NN SA631W ...

Page 39: ...10 2 SCHEMATIC DIAGRAM EXCEPT NN SD681S 39 NN SD681S NN SN671S NN SN661S NN SA661S NN SA651S NN SN651B NN SN651W NN SA631B NN SA631W ...

Page 40: ...40 NN SD681S NN SN671S NN SN661S NN SA661S NN SA651S NN SN651B NN SN651W NN SA631B NN SA631W ...

Page 41: ...R SWITCH 14 RE81 EVEJ1HF2224B REVOLVING ENCODER 1 ZD10 B0BA5R600016 ZENER DIODE 1 ZD180 DZ2J15000L ZENER DIODE 1 10 3 2 NN SN671S SN661S SN651B W Ref No Part No Part Name Description Pcs Set Remarks BZ210 L0DDEA000014 BUZZER 1 2 0KHz C10 F2A1H471B575 AL CHEM CAPACITOR 1 470µF 50V C11 F2A1C220B624 AL CHEM CAPACITOR 1 22µF 16V C482 F2A1H1R0B574 AL CHEM CAPACITOR 1 1µF 50V C483 F2A1HR47B574 AL CHEM C...

Page 42: ... F67525E20XN DIFFUSION SHEET 1 D40 D41 D189 D190 D221 D227 D228 D230 B0AACK000004 DIODE 8 D10 D13 B0EAKT000025 DIODE 4 IC1 MN69F009AC1 L S I 1 Q10 Q180 B1BAAJ000003 TRANSISTOR 2 D25 D4EAY271A036 ZENER RESISTOR 1 270V RY1 AEBGJQC25F18 POWER RELAY 1 T10 G4C2AAD00006 LOW VOLTAGE TRANSFORMER 1 120V ZD10 B0BA5R600016 ZENER DIODE 1 42 NN SD681S NN SN671S NN SN661S NN SA661S NN SA651S NN SN651B NN SN651W...

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