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Discharging the high voltage capacitors

WARNING

There is high voltage present with high current capabilities
in the circuits of the primary and secondary windings, choke
coil and heat sinkof the inverter. It is extremely dangerous
to work on or near these circuits with the oven energized.
DO NOT measure the voltage in the high voltage circuit
including the filament voltage of the magnetron.

WARNING

Never touch any circuit wiring with your hand or with an
insulated tool during operation.

3.3. Part replacement.

When troubleshooting any part or component is to be replaced,
always ensure that the power cord is unplugged from the wall
outlet.

3.4. When the 20A fuse is blown

due to the malfunction of the
monitor interlock switch:

WARNING

When the 20A 120V fuse is blown due to the malfunction of
the monitor interlock switch, replace all of the components
(primary latch switch, monitor interlock switch and power
relay RY1).
 1. This is mandatory. Refer to “measurements and

adjustments” for the location of these switches.

 2. When replacing the fuse, confirm that it has the

appropriate rating for these models.

 3. When replacing faulty switches, be sure the mounting

tabs are not bent, broken or deficient in their ability to
hold the switches.

3.5. Avoid inserting nails, wire etc.

through any holes in the unit
during operation.

Never insert a wire, nail or any other metal 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 tight before

inserting the plug into the wall outlet.

 3. Check for microwave energy leakage. (Refer to procedure

for measuring microwave energy leakage).

CAUTION OF MICROWAVE RADIATION LEAKAGE

USE CAUTION NOT TO BECOME EXPOSED TO
RADIATION FROM THE MICROWAVE MAGNETRON OR
OTHER PARTS CONDUCTING MICROWAVE ENERGY.

IMPORTANT NOTICE

 1. The following components have potentials above 2000V

while the appliance is operated.

  • 

Magnetron

  • 

High voltage transformer (Located on inverter (U))

  • 

High voltage diodes (Located on inverter (U))

  • 

High voltage capacitors (Located on inverter (U))

Pay special attention to these areas.

 2. When the appliance is operated with the door hinges or

magnetron installed incorrectly, the microwave leakage
can exceed more than 5mW/cm

2

. After repair or

exchange, it is very important to check if the magnetron
and the door hinges are correctly installed.

3.7. Sharp edges

CAUTION

Please use caution when disassembling or reassembling
internal parts. Some exposed edges may be sharp to the
touch and can cause injury if not handled with care.

9

NN-SD798S / NN-ST778S / NN-SA768W

Содержание NN-SD798S

Страница 1: ...ppliances Microwave Oven Shanghai Co Ltd All rights reserved Unauthorized copying and distribution is a violation of law NN SD798S NN ST778S NN SA768W RPH LATIN AMERICA RUH MEXICO Microwave Oven ORDER...

Страница 2: ...2 NN SD798S NN ST778S NN SA768W...

Страница 3: ...3 NN SD798S NN ST778S NN SA768W...

Страница 4: ...nterlock Switch 14 5 3 Magnetron 14 5 4 key board membrane Membrane switch assembly 14 5 5 Inverter power supply U 15 5 6 Temperature thermistor 15 6 MEASUREMENTS AND ADJUSTMENTS 16 6 1 Adjustment of...

Страница 5: ...1 SCHEMATIC DIAGRAM 5 NN SD798S NN ST778S NN SA768W...

Страница 6: ...e microcomputer in the DPC to determine 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...

Страница 7: ...d the Auto program selected is Oatmeal T2 T1 K 2 min and 40 sec 0 1 160sec 0 1 16 sec Category P1 Power P2 Power K Factor Standard Omelet MEDIUM MEDIUM 0 2 2 5 Sensor reheat Only for sensor models Aut...

Страница 8: ...inum 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...

Страница 9: ...on Never insert a wire nail or any other metal 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...

Страница 10: ...tors from D P C 2 Remove 1 grounding screw 3 Disconnect connector CN701 on H V Inverter board 4 Remove 1 screw holding escutcheon base and slide the escutcheon base upward slightly 5 Remove all screws...

Страница 11: ...fice 4 5 Door assembly 1 Remove door C from door E by carefully pulling outward starting from upper right hand corner using a flat blade screwdriver 2 Separate door E from tabs on door A and remove do...

Страница 12: ...OTE After reinstalling the new 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 scre...

Страница 13: ...ecause it is hot 1 Discharge high voltage charge 2 Remove 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 pla...

Страница 14: ...erlock Switch 1 Unplug lead 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...

Страница 15: ...stops in 37 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...

Страница 16: ...all latch switches again by following 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 H...

Страница 17: ...the start button 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 remove...

Страница 18: ...7 4 At least once a year have the radiation monitor checked for calibration by its manufacturer 18 NN SD798S NN ST778S NN SA768W...

Страница 19: ...body 7 120V AC is present on the digital programmer circuit Terminals of power relay s and primary circuit of Digital Programmer Circuit When troubleshooting be cautious of possible electrical shock h...

Страница 20: ...ch switches 2 Open or loose connection of high voltage circuit especially magnetron filament circuit NOTE Large contact resistance will cause lower magnetron filament voltage and cause magnetron to ha...

Страница 21: ...st you must program the DPC into TEST MODE press Clock pad once press Timer pad once Press Start pad once press Power Level pad once Program unit for operation H95 H97 H98 H99 appears in display windo...

Страница 22: ...netron wiring between 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 F606Y8M00AP 2 D702 is OK Replace magnetron Sh...

Страница 23: ...8 6 How to check the semiconductors using an OHM meter 23 NN SD798S NN ST778S NN SA768W...

Страница 24: ...9 EXPLODED VIEW AND PARTS LIST 9 1 EXPLODED VIEW 24 NN SD798S NN ST778S NN SA768W...

Страница 25: ...0 HOOK LEVER A 1 15 F31374650AP HOOK LEVER B 1 16 F31384650AP HOOK LEVER C 1 17 F400A4T00AP FAN MOTOR 1 AC120V SINGLE PHASE 60Hz 18 F40084T00AP FAN BLADE 1 19 F40254W00AP AIR GUIDE A 1 20 F40264T60APG...

Страница 26: ...Ref No Part No Part Name Description Pcs Set Remarks 49 F04468Y30RP FUNCTION LABEL 1 SD798S 52 F00066G00RP CAUTION LABEL 1 SD798S RPH ST778S RPH 26 NN SD798S NN ST778S NN SA768W...

Страница 27: ...E3 F800L8Y30SRP ESCUTCHEON BASE U 1 SD798S E4 F66167D00AP FLAT CABLE 1 SD798S E5 F82988N00SAP BUTTON 1 SD798S E6 F891P8N40SAP DOOR OPENING BUTTON U 1 SD798S E7 F82565X00AP DOOR OPENING LEVER 1 SD798S...

Страница 28: ...AU 1 ST778S E23 F800L8Y40SRP ESCUTCHEON BASE U 1 ST778S E26 F80724W70SAP DOOR OPENING BUTTON U 1 ST778S E27 F82564W00AP DOOR OPENING LEVER 1 ST778S E28 F80375K00AP COOK BUTTON SPRING 1 E29 F630Y8Y40BR...

Страница 29: ...T DU 1 SA768W E43 F80347C50HAP ESCUTCHEON BASE 1 SA768W E44 F66164W20AP FLAT CABLE 1 SA768W E45 F82987D60KAP BUTTON 1 SA768W E46 F80727C50HAP DOOR OPENING BUTTON 1 SA768W E47 F82565X00AP DOOR OPENING...

Страница 30: ...P DOOR A U 1 SD798S D2 F301A8R50SAP DOOR A U 1 ST778S D3 F302K4W00AP DOOR E U 1 D4 F30215G10XN DOOR KEY SPRING 1 D5 F30854W00AP DOOR C 1 D6 F31454W00AP DOOR SCREEN A 1 D7 F31468N20HAP DOOR SCREEN B 1...

Страница 31: ...RIALS Ref No Part No Part Name Description Pcs Set Remarks W1 F030A6P40AG LEAD WIRE HARNESS 1 W2 F030E6G30AP H V LEAD WIRE 1 W3 F03537B70AP LEAD WIRE HARNESS U 1 INCLUDING THERMISTOR 31 NN SD798S NN S...

Страница 32: ...RPH P2 F01028Y50HRP PACKING CASE PAPER 1 SA768W RPH P3 F01044W00AP UPPER FILLER 1 SD798S ST778S P3 F01045J00AP UPPER FILLER 1 SA768W P4 F01054W00AP LOWER FILLER 1 SD798S ST778S P4 F01055J00AP LOWER F...

Страница 33: ...10 DIGITAL PROGRAMMER CIRCUIT 10 1 NN SD778S 33 NN SD798S NN ST778S NN SA768W...

Страница 34: ...34 NN SD798S NN ST778S NN SA768W...

Страница 35: ...10 2 NN ST778S 35 NN SD798S NN ST778S NN SA768W...

Страница 36: ...36 NN SD798S NN ST778S NN SA768W...

Страница 37: ...10 3 NN SA768W 37 NN SD798S NN ST778S NN SA768W...

Страница 38: ...38 NN SD798S NN ST778S NN SA768W...

Страница 39: ...R 1 270 1 4W 5 R124 D0AE470JA155 CARBON FILM RESISTOR 1 47 1 4W 5 R229 D0AE680JA155 CARBON FILM RESISTOR 1 68 1 4W 5 RY1 AEBGJQC25F18 POWER RELAY 1 RY2 K6B1AZA00011 POWER RELAY 1 T10 G4C3AAD00006 LOW...

Страница 40: ...00E DIODE 7 D10 D11 D12 D13 B0EAKT000025 DIODE 4 D25 D4EAY271A036 ZENER RESISTOR 1 270V D26 D27 D4EAY112A036 ZENER RESISTOR 2 1100V R44 R10 R11 R311 D0AE102JA155 CARBON FILM RESISTOR 4 1K 1 4W 5 R12 D...

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