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H. V. Diode

Short

H. V. Capacitor

1-2 Special Servicing Precautions (Continued)

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.

1-3 Special High Voltage Precautions

1. High Voltage Warning

Do not attempt to measureany 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 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 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.

PRECAUTION

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

Fig. 1-1 Discharging High Voltage Capacitor

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

Summary of Contents for CE2777R-S

Page 1: ...ENTS MICROWAVE OVEN 1 Precaution 2 Specifications 3 Operating Instructions 4 Disassembly and Reassembly 5 Alignment and Adjustments 6 Trouble 7 Exploded Views and Parts List 8 PCB Diagrams 9 Schematic Diagrams Manual CE2777R S CE2777R ...

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: ...e 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 and power ...

Page 4: ...ure 1 1 2 The high voltage capacitor 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 ...

Page 5: ...REQUENCY MAGNETRON COOLING METHOD OUTSIDE DIMENSIONS OVEN CAVITY DIMESIONS SHIPPING WEIGHT APPROX 99 MINUTES 230V 50Hz AC MICROWAVE 1 400W GRILL 1100W COMBI 2500W FROM 100 TO 850W IEC 705 TEST PROCEDURE 2 450MHz OM75PH 31 COOLING FAN MOTOR 489 W x 275 H x 415 D 305 W x 201 H x 322 D NET 16 0kg GROSS 17 5kg ...

Page 6: ...oor Latches Ventilation Holes Glass Tray Light Safety Interlock Holes Coupler Door Guide Roller 357mm 489mm 200mm 275mm 415mm CLOCK SETTING DISPLAY AUTO REHEAT COOK SELECTION POWER LEVEL SETTING COMBI BUTTON START DIAL KNOB GRILL BUTTON AUTO POWER DEFROST BUTTON STOP CANCEL BUTTON ...

Page 7: ...oes 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 Servicemen ...

Page 8: ...C to remove Door C Be careful when handling Door C because it is fragile 4 3 3 Removal of Key Door Spring 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 les 4 3 4 Removal of Key Door Spring Remove pin hinge from Door E Detach spring from Door E and...

Page 9: ...ate 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 securing ...

Page 10: ...ver touch the control circult 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 Remonal of Ass y P C B Assembly 1 Remove screws securing the control circuit board 2 Lift up the control circuit board from the Ass y control box SCREWS ASSY PCB ...

Page 11: ... shorted magnetron 2 Isolate the magnetron 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 Primary Terminals Filament Terminals Secondary Terminal Magnetron Antenna Gasket Plate Cooling Fins PRECAUTION 1 High voltage is pre...

Page 12: ...nd Monitor Switch 1 When mounting Primary switch and Interlock Monitor switch to Latch Body consult 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 ...

Page 13: ...ure 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 5 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...

Page 14: ...t 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 arnear 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 neading should be less than 4mW cm 2 5 12 Note on Measurement 1 Do not exceed the limited scal...

Page 15: ...dure 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 Defective hig...

Page 16: ...ain 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 interloc...

Page 17: ...4 MM27 MM28 MM67 MM52 MM06 MM171 MM05 MM55 MM26 MM61 MM68 MM109 MM60 MM57 MM17 MM08 MM09 MB01 MM07 MM25 MM59 MM21 MM18 MM19 MM20 MM64 MM03 MM32 MM10 MM88 MB05 MB03 MB03 MB02 MB04 MD04 MD06 MD05 MD11 MD14 MD191 MD03 MD02 MD24 MD10 MD01 MD07 MD19 MC13 MC142 MC141 MC31 MC27 MC143 MC01 MC03 MC06 MC07 MC15 MC10 ...

Page 18: ...7 2 Main Parts List 0 0 ...

Page 19: ...7 3 Control Parts List S N A SERVICE NOT ASSEMBLY 0 0 1 ...

Page 20: ...7 4 Door Parts List 2 2 ...

Page 21: ...7 5 Standard Parts List 2 2 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 3 0 2 ...

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

Page 23: ...8 2 P C B Parts List 45 67 45 3 3 3 8 8 8 8 49 7 8 8 0 2 2 49 0 8 0 0 0 8 8 33 3 3 ...

Page 24: ...9 Schematic Diagrams 9 1 Schematic Diagrams RED RED BRN BLK FA F HIGH VOLTAGE TRANSFORMER H V FUSE HIGH VOLTAGE CAPACITOR HIGH VOLTAGE DIODE TO CHASSI MAGNETRON RED RED ...

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