background image

17. When checking the continuity of the witches

or transformer, always make sure that the
power is OFF, and one of the lead wires is
disconnected.  

18. Components that are critical for safety are

indicated in the circuit diagram by
shading,    

or      .  

19. Use replacement components that have the

same ratings, especially for flame resistance
and dielectric strength specifications. A
replacement part that does not have the
same safety characteristics as the original
might create shock, fire or other hazards. 

1. High Voltage Warning

Do not attempt to measure any of the high
voltages--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.)

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. 

1-2

Pretaution

Samsung Electronics

1-2 Special Servicing  Precautions (Continued)

1-3  Special High Voltage Precautions

PRECAUTION

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

PRECAUTION

There exists HIGH VOLTAGE ELECTRICITY with high
current capabilities in the circuits of the HIGH VOLTAGE
TRANSFORMER secondary and filament terminals. 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 filament voltage of magnetron.

PRECAUTION

Never touch any circuit wiring with your hand nor with
uninsulated tool during operation.

H. V. Diode

Short

H. V. Capacitor

Touch chassis ground first then short to the high
voltage capacitor terminal by using screwdriver or
jumper wire.

Summary of Contents for MG7980W

Page 1: ...CEManual MICROWAVE OVEN CONTENTS 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 ...

Page 2: ...hes 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 and power relay 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 Alteratio...

Page 3: ...ive terminal of the high voltage capacitor 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 1 2 Pretaution Samsung Electronics 1 2 Special Servicing Precautions Continued 1 3 Special High Voltage Precautions PRE...

Page 4: ... SOURCE 120V 60HZ AC POWER CONSUMPTION MICROWAVE 1 400W HEATER 1 300W OUTPUT POWER FROM 100W TO 1000W 10 LEVEL POWER IEC 705 TEST PROCEDURE OPERATING FREQUENCY 2 450MHz MAGNETRON OM75PH 31 ESS COOLING METHOD COOLING FAN MOTOR OUTSIDE DIMENSIONS 2121 32 W x 1212 32 H x 1715 32 D NET WEIGHT 44 1 lbs SHIPPING WEIGHT 50 7 lbs ...

Page 5: ...Instant Cook Button Browner Button Auto Defrost Button Auto Reheat Button Number Key Button Start Button Sound Button Clock Auto Start Button Hold Timer Button Power Level Button More Less Button Pause Cancel Button 3 Operating Instructions 3 1 Control Panel 3 2 Features External Views Door VentilationHole Light SafetyInterlockHoles Heater ControlPanel OpenDoorPush Button GuideRoller MetalRack Gla...

Page 6: ...ed 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 capacitor 2 Disconnect all the leads 3 Remove the mounting bolts 4 Reconnect the leads correctly and firmly 4 2 Replacement of High Voltage Transformer Lamp Cover Air Magnetron H V Trans H V Capacitor Thermo S W Fan Motor B...

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 Key Door Spring Door E Disassembly and Reassembly Upper...

Page 8: ...oor sensing switch monitor switch and power relay 3 When the above three switches operate properly check if any other part such as the control circuit board blower motor or high voltage transformer is defective 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 replacement of the defective component p...

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: ... 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 3 Before t...

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 T 0 88xMcx T2 T0 Output Power 41 87 41 87 Heating Time sec 4 187 Coefficient for Water 1000 Water cc T Temperature Rise T2 T1 Mc Cylindrical borosilicate glass weight To Room temperature 5 8 Output Power of Magnetron Alignment an...

Page 13: ...repair of a radiarion preventing device make a repair record for the measured values and keep the data 2 If the radiation leakage is more than 4 mW cm2 after determining that all parts are in good condition functioning properly and the identical parts are replaced as listed in this manual notift that fact to CENTRAL SERVICE CENTER 5 13 2 At least once a year have the microwave energy survey meter ...

Page 14: ... sensing 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 ...

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: ... sensing 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 ...

Page 17: ...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 18: ...loded Views 7 1 M1 M27 M29 M36 C1 C2 C3 C4 C5 C6 C7 M35 M18 M21 M23 M19 M37 M38 M39 M25 M26 M2 M33 M5 M28 M34 M6 M9 M10 M13 M15 M16 M17 B1 B2 B2 B4 B3 M7 M8 M12 M41 D1 D10 D2 D3 D5 D6 D9 D4 D7 D8 M40 M24 M20 M14 M11 M22 M31 M30 M3 M32 M4 M42 M43 M44 M45 M46 M47 ...

Page 19: ...CKET HVC SECC T0 8 W31 L125 8 1 M22 2501 001106 C OIL 910nF 2 1KV BK 54x35x75 20mm 1 M23 DE59 40001A DIODE H V HVR 1X 32B 12 1 M24 DE65 20025A CABLE CLAMP DAWS 2NB NYLON66 NTR WIRE SADD 1 M25 DE61 40066A FOOT PP BLK 3RD W 2 M26 DE80 10002A BASE PLATE SGCC T 0 8 W 404 L 633 MW65 1 M27 DE31 10154A MOTOR DRIVE M2HJ49ZR02 ST 16 50 60HZ 1 M28 DE47 20173A THERMOSTAT PW 2N 90 60 30 187Y 250V7 5A 9 1 CV T...

Page 20: ...ACE ACRYL T0 45 W9 WHT WF103 4420 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 M945 1 C 2 DE61 70076A SPRING BUTTON HSWR PI0 6 1 C 3 DE34 10206Y SWITCH MEMBRANE PE SHEET W89 7 L199 8 MG7980W 1 C 4 DE72 70005A CONTROL PANEL ABS VH0853 164G PURE WHT T2 5 1 C 5 DE67 40002A WINDOW DISPLAY RESIN ACRYLIC T2 3 M945 ID...

Page 21: ...ED 2 C BACK DE60 10082H SCREW A 2S 4X12 TOOTHED 2 CN BOX DE60 10082H SCREW A 2S 4X12 TOOTHED 1 CV AIR DE60 10082H SCREW A 2S 4X12 TOOTHED 2 LATCH DE60 10082H SCREW A 2S 4X12 TOOTHED 5 PN OUT DE60 10098A SCREW ASSY TAP TITE PH TC M4X8 SWRCH18A ZPC2 GLD W 1 CV TCO DE60 10098A SCREW ASSY TAP TITE PH TC M4X8 SWRCH18A ZPC2 GLD W 2 M DRIV DE60 10122A SCREW TAP TH TAP TH 2 4X8 FE FN 2 B EART DE60 10122A ...

Page 22: ...8 P C B Diagrams 8 1 P C B Diagrams Samsung Electronics 8 1 ...

Page 23: ...6 R07 R11 R12 P21 2001 000515 R CARBON 220OHM 5 1 8W AA TP 1 8X3 2MM 1 R09 P22 2001 000577 R CARBON 2KOHM 5 1 8W AA TP 1 8X3 2MM 1 R13 P23 2001 000613 R CARBON 3 9KOHM 5 1 8W AA TP 1 8X3 2MM 5 R16 R18 R20 R26 R27 P23 2001 000613 R CARBON 3 9KOHM 5 1 8W AA TP 1 8X3 2MM 3 R28 R29 R30 P24 2001 000780 R CARBON 470OHM 5 1 8W AA TP 1 8X3 2MM 2 R01 R02 P25 2001 000786 R CARBON 47KOHM 5 1 8W AA TP 1 8X3 2...

Page 24: ...NG 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 CHASSIS ...

Reviews: