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4-6 Replacement of Control Circuit Board

4-6-1 Removal of Control Box Assembly

4-4

Samsung Electronics

1. Be sure to ground any static electric charge in

your body and never touch the control circuit.

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.

1. Pull the lever end of the plastic fastener and

remove the Flexible Printed Circuit(FPC) of
membrane panel.

2. Remove screws securing the control circuit

board.

3. Lift up the control circuit board from the Ass'y

control box.

4. When reconnecting the FPC connector, make

sure that the holes on the connector are properly
engaged with the hooks on the Plastic Fastener.

1. Window display should not be disassembled as

its mounting tabs will be broken. If repair work
is difficult, replace with Ass'y control panel.

2. The membrane key board is attached to the

escutcheon base with doublefaced adhesive
tape. Therefore, applying hot air such as using
of hair dryer is recommended for smoother
removal.

3. When installing new membrane key board,

make sure that the surface of escutcheon base is
cleaned sufficiently so that any problems
(shorted contacts or uneven surface) can be
avoided.

4-6-2 Removal of P.C.B Assembly

4-6-3 Removal of Window Display & Membrane Panel

Disassembly and Reassembly

Control Box

FPC Connector

Screw

Screw

Membrane

Panel

Window

Display

Summary of Contents for MB6774W

Page 1: ...ly 5 Alignment and Adjustments 6 Troubleshooting 7 Exploded Views and Parts List 8 PCB Diagrams 9 Schematic Diagrams SAMTRONICS One Minute Help Screen Browner Baby Food Frozen Dinner Custom Potoato Fresh Vegetable Power Level Auto Start Hold Timer More Less 1 2 3 4 5 6 7 8 9 0 Auto Defrost Auto Reheat Clock Sound Pause Cancel Start Diet Cook Popcorn ...

Page 2: ...k 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 and secondary switches as well as the Interlock Monitor Switch The correct adjustment of these switches is described elsewhere in this manual Make sure that the fuse has the correct rating for the particular model being repaired 13 Design Alteration Warn...

Page 3: ...ages this includes the filament voltage of the magnetron High voltage is present during any cook cycle Before touching any components or wiring always unplug the oven and discharge the high voltage capacitor See Figure 1 1 2 The high voltage capacitor remains charged about 30 seconds after disconnection Short the negative terminal of the high voltage capacitor to the oven chassis Use a screwdriver...

Page 4: ...10 LEVEL POWER IEC 705 TEST PROCEDURE HEATER 1000W OPERATING FREQUENCY 2 450MHz MAGNETRON OM75PH 31 ESS COOLING METHOD COOLING FAN MOTOR OUTSIDE DIMENSIONS 21291 32 W x 1212 32 H x 1715 32 D NET WEIGHT 41 9 lbs SHIPPING WEIGHT 47 4 lbs 2 2 Comparison Chart MODEL FEATURE MORE LESS AUTO REHEAT AUTO DEFROST TIME COOK POWER LEVEL INSTANT COOK MEMORY CHILD LOCK CLOCK AUTO START BROWNER COOK SOUND DEMO ...

Page 5: ...ating Instructions 3 1 Control Panel Samsung Electronics 3 1 3 2 Features External Views Door VentilationSlot Light SafetyInterlockHoles HeaterElements ControlPanel OpenDoorPush Button GuideRoller MetalRack GlassTray DoorLatches One Minute Help Screen Browner Diet Cook Baby Food Frozen Dinner Custom ll Potoato Fresh Vegetable Custom l Power Level Auto Start Hold Timer More Less 1 2 3 4 5 6 7 8 9 0...

Page 6: ...motor assembly 6 Take out the fan motor assembly 7 Remove the oven lamp by pulling out from hole of air cover NOTE1 When removing the magnetron make sure that its antenna 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 1 Discharge the high voltage ca...

Page 7: ... C because it is fragile 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 Remove pin hinge from Door E Detach spring from Door E and key door 4 3 2 Removal of Door C 4 3 3 Removal of Door E Disassembly and Reassembly Upper Hinge Lower Hinge Scre...

Page 8: ... 6 Remove the drive motor and the coupler 7 When replacing the drive motor be sure to remount it in the correct position with the coupler 8 Connect all the leads to the drive motor 9 Screw the drive motor cover to the base plate with a screw driver 4 4 Replacement of Fuse 4 5 Replacement of Drive Motor Disassembly and Reassembly Screw Drive Motor Cover Base Plate Thermo Switch Drive Motor After re...

Page 9: ...cting the FPC connector make sure that the holes on the connector are properly engaged with the hooks on the Plastic Fastener 1 Window display should not be disassembled as its mounting tabs will be broken If repair work is difficult replace with Ass y control panel 2 The membrane key board is attached to the escutcheon base with doublefaced adhesive tape Therefore applying hot air such as using o...

Page 10: ...d magnetron case should read open 1 The low voltage transformer is located on the control circuit board 2 Remove the low voltage transformer from the PCB Ass y and check continuity 3 Normal resistor reading is shown in the table PRECAUTION 1 High voltage is present at the high voltage terminals during any cook cycle 2 It is neither necessary nor advisable to attempt measurement of the high voltage...

Page 11: ...n 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 Completely tighten the screws holding the Latch Body to the oven assembly 4 Reconnect to Monitor switch and check the continuity of the monitor circuit and all latch switche...

Page 12: ...rise is marginal NOTE 2 Output power in watts is computed by multiplying the temperature rise step 5 by a factor of 91 times the of centigrade temperature 4 187 x 1000 x DT 0 88xMcx T2 T0 Output Power 41 87 41 87 Heating Time sec 4 187 Coefficient for Water 1000 Water cc DT Temperature Rise T2 T1 Mc Cylindrical borosilicate glass weight To Room temperature 5 8 Output Power of Magnetron Alignment a...

Page 13: ... when the operator s hand is between the handle and the probe 3 When high leakage is suspected do not move the probe horizontally along the oven surface this may cause damage to the probe 4 Follow the recommendation of the manufacturer of the microwave energy survey meter 1 Pour 275 15cc of 20 5 68 9 water in a beaker which is graduated to 600cc and place the beaker in the center of the oven 2 Sta...

Page 14: ...ng switch 3 Defective monitor switch NOTE1 4 Shorted HVCapacitor 5 Shorted HVTransformer NOTE2 NOTE 1 All of these switches must be replaced at the same time refer to adjustment instructions Check continuity of power relay contacts and if it has continuity replace power relay also NOTE 2 When HVTransformer is replaced check diode and magnetron also Oven does not accept 1 Key input is not in Sequen...

Page 15: ...d 1 Loose fan and fan motor Tighten screws of fan motor 2 Loose screws on H V Transformer Tighten screws of H V Transformer 3 Shorted H V Diode Replace H V Diode Turntable motor does not rotate 1 Open or loose wiring of turntable motor Check the wire of turntable motor 2 Defective turntable motor Replace turntable motor Oven stops operation during cooking 1 Open or loose wiring of primary Adjust d...

Page 16: ...28 M6 M9 M10 M13 M15 M16 M17 B1 B2 B4 B3 B5 M7 M8 D1 D2 D3 D5 D6 D9 D10 D4 D7 D8 M30 M40 M24 M20 M14 M4 M11 M12 On e Mi nu te He lp Scr een Bro wn er Pop cor n Die t Coo k Fro zen Din ner Cus tom Pot oat o Fre sh Veg etab le Bab y Foo d Pow er Lev el Aut o Star t Hol d Tim er Mo re Les s 1 2 3 4 5 6 7 8 9 0 Aut o Def ros t Aut o Reh eat Clo ck Sou nd Pau se Can cel Sta rt M22 ...

Page 17: ...0 01 NTR MW5630T 1 M 19 DE26 10126A TRANS H V SHV 6574DC1 220V 60HZ DY 2310V 3 1 M 20 DE63 90163A CUSHION HVT NEOPRENE RUBBER T29 5 W50 L5 1 M 21 DE61 50106A BRACKET HVC SECC T0 8 W31 L125 8 1 M 22 2501 001011 C OIL 910pF 2100V BK 54x35x75mm 20mm 1 M 23 DE59 40001A DIODE H V HVR 1X 32B 12 1 M 24 DE39 30024A WIRE LEAD C 3EAO L1900 1 M 25 DE61 40017A FOOT PP A353 BLK MW5630T 2 M 26 DE80 10002A BASE ...

Page 18: ...ACE ACRYL T0 45 W9 WHT WF103 1 7 4 Control Parts List Ref No Parts No Description Specification Q ty Remarks C 1 DE66 20006A BUTTON PUSH RESIN ABS HR 0370U P WHT M9 1 MB6774W C 1 DE66 20006B BUTTON PUSH ABS HR 0370 GRAY MW5575G IDEO 1 MB6775G C 2 DE61 70076A SPRING BUTTON HSWR PI0 6 1 C 3 DE34 10206T SWITCH MEMBRANE PET 220V 60HZ MB6774W SAM 1 MB6774W C 3 DE34 10206U SWITCH MEMBRANE PET 220V 60HZ ...

Page 19: ...H TH M4 L8 STS 2 B HEA DE60 10082A SCREW A M4 L12 2S TOOTHED 4 B UPP DE60 10080A SCREW WASHER M5 L12 2S 4 MGT DE60 10189A SCREW MACHINE TH M4 L10 FE FZ YEL N 2 HI LOW DE60 10082A SCREW A M4 L12 2S TOOTHED 1 CV AIR DE60 10082A SCREW A M4 L12 2S TOOTHED 1 B MGT DE60 10082A SCREW A M4 L12 2S TOOTHED 1 P EART DE60 10082A SCREW A M4 L12 2S TOOTHED 5 OPANEL DE60 10082A SCREW A M4 L12 2S TOOTHED 1 MEM PN...

Page 20: ...8 P C B Diagrams 8 1 P C B Diagrams Samsung Electronics 8 1 MB6774W ...

Page 21: ...C CERAMIC MLC AXIAL TP050F103ZB 10NF 80 1 C10 2202 000780 C CERAMIC MLC AXIAL UP050F104Z 100NF 80 4 C5 7 1 2401 000247 C AL 1SA1ANB107MAN 100UF 20 10V GP 6 3X 1 C14 2401 000466 C AL CESSM1V100M0507 10UF 20 35V GP 5X7 1 C08 2401 000914 C AL CESSL1C220M0511AA 22UF 20 16V GP 5 1 C03 2401 001412 C AL 1SG1VFB477MAN 470UF 20 35V GP 10X1 1 C1 2 2802 000161 RESONATOR CERAMIC CST4 00MGW TF01 3 CN 4 1 X TAL...

Page 22: ...WARNING NOTE CIRCUIT SHOWN WITH DOOR IS OPENED POSITION NOTE FOR SERVICE REPLACEMENT USE 16 GA 105 C THERMOPLASTIC COVERED WIRE EXCEPT FOR HIGH VOLTAGE LEADS OR AS NOTED ON SPECIAL LEADS 1 INPUT 120V 60HZ 2 DOOR OPEN 3 LAMP ON 4 P C B PATTERN 5 P C B IN OUT POINT MGT TCO COM NC 120V 130V 40W 21V 0V NO L FM DM BLK BLK R RED RED ORG WHT BLK WHT ORG ORG WHT BLU BLK MAGNETRON HIGH VOLTAGE DIODE TO CHA...

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