Samsung M1874NR Service Manual Download

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SRSC

SERVICE

MICROWAVE OVEN

CONTENTS

MICROWAVE OVEN

1. Precaution

2. Specifications

3. Operating Instructions

4. Disassembly and Reassembly

5. Alignment and Adjustments

6. Troubleshooting

7. Exploded Views and Parts List

8. PCB Diagrams

9. Schematic Diagrams

Manual

M1874NR

Summary of Contents for M1874NR

Page 1: ...TENTS MICROWAVE OVEN 1 Precaution 2 Specifications 3 Operating Instructions 4 Disassembly and Reassembly 5 Alignment and Adjustments 6 Troubleshooting 7 Exploded Views and Parts List 8 PCB Diagrams 9 Schematic Diagrams Manual M1874NR ...

Page 2: ...s and latches 5 evidence of dropping or abuse c Before turning on microwave power for any service test or inspection within the microwave generating compartments check the magnetron wave guide or transmission line and cavity for proper alignment integrity and connections d Any defective or misadjusted components in the interlock monitor door seal and microwave generation and transmission systems s...

Page 3: ...hould remove their watches while repairing an MWO 11 To avoid any possible radiation hazard replace parts in accordance with the wiring diagram Also use only the exact replacements for the following parts Primary and secondary interlock switches interlock monitor switch 12 If the fuse is blown by the Interlock Monitor Switch Replace all of the following at the same time Primary door sensing switch...

Page 4: ...acitor remains charged about 30 seconds after disconnection Short the negative terminal of the high voltage capacitor to to the oven chassis Use a screwdriver 3 High voltage is maintained within specified limits by close tolerance safety related components and adjustments If the high voltage exceeds the specified limits check each of the special components PRECAUTION There exists HIGH VOLTAGE ELEC...

Page 5: ...AGNETRON COOLING METHOD OUTSIDE DIMENSIONS SHIPPING DIMENSIONS OVEN DIMENSIONS SHIPPING WEIGHT APPROX 99 MINUTES 230V 50Hz AC MICROWAVE 1 150W FROM 100 TO 800W IEC 705 TEST PROCEDURE 2 450MHz OM75S 31 ESS COOLING FAN MOTOR 489 W x 275 H x 370 D mm 557 W x 329 H x 434 D mm 306 E x 211 H x 320 D mm NET 14 0kg GROSS 16 0kg ...

Page 6: ...ting Instructions 3 1 Control Panel 3 2 Features External Views Door Ventilation Holes Light Safety Interlock Hole Control Panel Roller Ring Coupler Glass Plate Door Latches 30 s 1 2 3 4 5 342mm 275mm 370mm 206mm ...

Page 7: ... does not hit any adjacent parts or it may be damaged NOTE2 When replacing the magnetron be sure to remount the magnetron gasket in the correct position and make sure the gasket is in good condition 4 2 Replacement of High Voltage Transformer 1 Discharge the high voltage capacitor 2 Disconnect all the leads 3 Remove the mounting bolts 4 Reconnect the leads correctly and firmly PRECAUTION Serviceme...

Page 8: ...hen remove the assembly 4 3 2 Removal of Door E Following the procedure as shown in the figure insert and bend a thin metal plate between Door E and Door A until you hear the tick sound 1 Insertion depth of the thin metal plate should be 0 5mm or less 4 3 3 Removal of Key Door Spring Remove pin hinge from Door E Detach spring from Door E and key door Door E Key Door Spring Door A Door C Door E ...

Page 9: ...operate properly check if any other part such as the control circuit board blower motor or high voltage transformer is defective 4 5 Replacement of Drive Motor 1 Take out the glass tray guide roller and coupler from cavity 2 Turn the oven upside down to replace the drive motor 3 Remove a screw securing the drive motor cover 4 Disconnect all the lead wires from the drive motor 5 Remove screws secur...

Page 10: ... touch control circuitry 2 Disconnect the connectors from the control circuit board 3 Remove screws securing the control box assembly 4 Remove the screw securing the ground tail of the keyboard 4 6 2 Removal of Ass y P C B 1 Remove screws securing the control circuit board 2 Lift up the control circuit board from the Ass y control box CONTROL BOX SCREW SCREW ...

Page 11: ...etron from the circuit by disconnecting its leads 3 A continuity check across the magnetron filament terminals should indicate one ohm or less 4 A continuity check between each filament terminal and magnetron case should read open Terminals Resistance 1 2 Input 3 4 Output 2 9V 5 6 Output13V 1 000 Ω 3 947 Ω 2 117 Ω Primary Terminals Filament Terminals Secondary Terminal Magnetron Antenna Gasket Pla...

Page 12: ...lt the figure 2 No specific adjustment during installation of Primary switch and Monitor switch to the latch body is necessary 3 When mounting the Latch Body to the oven assembly adjust the Latch Body by moving it so that the oven door will not have any play in it Check for play in the door by pulling the door assembly Make sure that the latch keys move smoothly after adjustment is completed Compl...

Page 13: ...e will cause a variance in the temperature rise Additional power test should be made if temperature rise is marginal NOTE 2 Output power in watts is computed by multiplying the temperature rise step E by a factor of 91 times the of centigrade temperature 5 9 Microwave Heat Distribution Heat Evenness The microwave heat distribution can be checked indirectly by measuring the water temperature rise a...

Page 14: ...en at the highest power level 4 Set survey meter dual ranges to 2 450MHz 5 Using the survey meter and spacer cone as described above measure near the opening of magnetron the surface of the air guide and the surface of the wave guide as shown in the following photo but avoid the high voltage components The reading should be less than 4mW cm2 5 12 Note on Measurement 1 Do not exceed the limited sca...

Page 15: ... procedure Replace PCB main Timer starts countdown but no microwave oscillation No heat while oven lamp and fan motor turn on 1 Off alignment of latch switches 2 Open or loose connection of high voltage circuit especially magnetron filament circuit NOTE Large contact resistance will bring lower magnetron filament voltage and cause magnetron to lower output and or intermittent oscillation 3 Defecti...

Page 16: ... main Loud buzzing noise can be heard 1 Loose fan and fan motor 2 Loose screws on H V Transformer 3 Shorted H V Diode Tighten screws of fan motor Tighten screws of H V Transformer Replace H V Diode Turntable motor does not rotate 1 Open or loose wiring of turntable motor 2 Defective turntable motor Replace turntable motor Oven stops operation during cooking 1 Open or loose wiring of primary interl...

Page 17: ...M07 MM16 MM03 MM14 MM09 MM30 MM31 MM32 MM27 MM55 MM22 MM88 MM05 MM26 MM06 MM17 MM08 MM10 MM19 MM20 MM18 MM29 MC01 MD14 MD02 MD03 MD04 MD07 MD10 MD06 MD24 MC141 MC17 MC04 MC27 MC03 MC15 MC142 MC23 MC07 MC41 MC10 MC13 MC06 MD01 MD05 MD11 MB01 MB05 MB03 MB02 MB042 MB041 ...

Page 18: ...1 MM10 4713 001031 LAMP INCANDESCENT 230V 173mA 40W ORG 25x69mm 1 MM14 DE26 00059A TRANS H V SHV E1713A 230V 50HZ 2130V 3 65V 1 MM16 DE71 00151A COVER MGT MW850WA PP T2 W54 L129 GE WHT NC2000 1 MM17 DE47 20173A THERMOSTAT PW 2N 90 60 30 187Y 250V7 5A 9 1 MM18 DE74 20102B TRAY COOKING GLASS T5 0 M745 1 MM19 DE97 00193B ASSY GUIDE ROLLER NC2000 0 6 T2 P1198 14PI 1 MM20 DE67 00140A COUPLER NC2000 0 6...

Page 19: ...1 00005R COVER PANEL M1774R BWT ABS HR0370 M1774R BWT 1 MC23 DE67 00036A BUTTON CLOCK M1774 1 MC27 DE67 00037A BUTTON CANCEL M1774 1 MC41 DE63 00016A CUSHION PCB M1774 1 PUT FOAM PUT FOAM T20 W85 5 L50 1 MD01 ASSY DOOR M1814NR M1874NR BWT PURE WHT CIS FISH 1 S N A MD02 DE64 40277B DOOR A FISH ABS HR 0370 M759 M759R WHT W9501 1 MD03 DE64 40278K SCREEN DOOR ACRYL SMOG M1714R BWT RUSSIA 1 MD04 DE92 5...

Page 20: ...SWRCH18A ZP2 PH PI5 L10 4 MGT DE60 10082H SCREW A 2S 4X12 TOOTHED 1 AIR COVER DE60 10082H SCREW A 2S 4X12 TOOTHED 2 B LATCH DE60 10082H SCREW A 2S 4X12 TOOTHED 3 B PLATE DE60 10082H SCREW A 2S 4X12 TOOTHED 1 C BLOWER DE60 10082H SCREW A 2S 4X12 TOOTHED 1 C BOX DE60 10082H SCREW A 2S 4X12 TOOTHED 4 O PANEL DE60 10098A SCREW ASSY TAP TITE GLD SWRCH18A ZPC2 PH TC M4X8 WT 1 D MOTOR DE60 30016A NUT FLA...

Page 21: ... 19 8 P C B Diagrams 8 1 P C B Diagrams ...

Page 22: ...404 001194 THERMISTOR PTC 39ohm 20 220 240V 270Vac 1 2A TP 1 PTC1 2007 000300 R CHIP 10KOHM 5 1 10W DA TP 2012 7 R08 11 32 34 37 38 2007 000451 R CHIP 180OHM 5 1 8W DA TP 3216 8 R17 24 2007 000468 R CHIP 1KOHM 5 1 10W DA TP 2012 10 R03 04 06 16 29 31 35 36 41 2007 000546 R CHIP 20KOHM 5 1 10W DA TP 2012 1 R05 2007 000671 R CHIP 2KOHM 5 1 10W DA TP 2012 5 R01 02 09 10 39 2007 000931 R CHIP 470OHM 5...

Page 23: ...R SENSING SWITCH INRUSH RELAY POWER RELAY SECONDARY INTERLOCK MAIN RELAY L V TRANS 2200pF 0 1uF 1mH 2200pF 250V10A FUSE 500K P T C YEL 21V 0V BRN BRN BROWN RED RED BLU BLUE YEL YELLOW Y G YELLOW GREEN ORG ORANGE WHT WHITE BLK BLACK GRN GREEN SYMBOL COLOR NOTE 1 INPUT 230V 2 DOOR OPEN 3 LAMP ON 4 ASSY NOISE FILTER PATTERN 5 PCB PATTERN L F M D M RED RED BRN BLU FA F HIGH VOLTAGE TRANSFORMER H V FUS...

Page 24: ... Samsung Electronics Co Ltd September 2001 Printed in Korea Code No DE68 02304A ELECTRONICS ...

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