Dacor DCM24B Service Manual Download Page 4

1

DCM24B
DCM24R
DCM24S

WARNING TO SERVICE PERSONNEL

Microwave ovens contain circuitry capable of pro-
ducing very high voltage and current, contact with
following parts   may result in a severe, possibly
fatal, electrical shock.

(Example)

High Voltage Capacitor, High Voltage Power Trans-
former, Magnetron, High Voltage Rectifier Assem-
bly,  High Voltage Harness etc..

Read the Service Manual carefully and follow all
instructions.

Before Servicing

1. Disconnect the power supply cord

,  and then

remove outer case.

2. Open the door and block it open.
3. Discharge high voltage capacitor.

WARNING:RISK OF ELECTRIC SHOCK.

DISCHARGE THE HIGH-VOLTAGE
CAPACITOR BEFORE SERVICING.

The high-voltage capacitor remains charged about 60
seconds after the oven has been switched off. Wait for 60
seconds and then short-circuit the connection of the high-
voltage capacitor (that is the connecting lead of the high-
voltage rectifier) against the chassis with the use of an
insulated screwdriver.

Whenever troubleshooting is performed the power supply
must be disconnected. It may, in some cases, be necessary
to connect the power supply after the outer case has been
removed, in this event,
1. Disconnect the power supply cord, and then remove

outer case.

2. Open the door and block it open.
3. Discharge high voltage capacitor.
4. Disconnect the leads to the primary of the power

transformer.

5. Ensure that the leads remain isolated from other

components and oven chassis by using insulation tape.

6. After that procedure, reconnect the power supply cord.

When the testing is completed,

1. Disconnect the power supply cord, and then remove

outer case.

2. Open the door and block it open.
3. Discharge high voltage capacitor.
4. Reconnect the leads to the primary of the power

transformer.

5. Reinstall the outer case (cabinet).
6. Reconnect the power supply cord after the outer case is

installed.

7. Run the oven and check all functions.

After repairing

1. Reconnect all leads removed from components during

testing.

2. Reinstall the outer case (cabinet).
3. Reconnect the power supply cord after the outer case is

installed.

4. Run the oven and check all functions.

Microwave ovens should not be run empty. To test for the
presence of microwave energy within a cavity, place a cup
of cold water on the oven turntable, close the door and set
the power to HIGH and set the microwave timer for two (2)
minutes. When the two minutes has elapsed (timer at zero)
carefully check that the water is now hot. If the water
remains cold carry out Before Servicing procedure and re-
examine the connections to the component being tested.

When all service work is completed and the oven is fully
assembled, the microwave power output should be checked
and a microwave leakage test should be  carried out.

Don't Touch !
Danger High Voltage

Summary of Contents for DCM24B

Page 1: ...DCM Convection Microwave Parts and Service Manual...

Page 2: ...h Voltage Harness etc Page PRECAUTIONS TO BE OBSERVED BEFORE AND DURING SERVICE TO AVOID POSSIBLE EXPOSURE TO EXCESSIVE MICROWAVE ENERGY INSIDE FRONT COVER BEFORE SERVICING INSIDE FRONT COVER WARNING...

Page 3: ...transmission systems shall be repaired replaced or adjusted by procedures described in this manual before the oven is released to the owner e A microwave leakage check to verify compliance with the F...

Page 4: ...pacitor 4 Disconnect the leads to the primary of the power transformer 5 Ensure that the leads remain isolated from other components and oven chassis by using insulation tape 6 After that procedure re...

Page 5: ...of the oven cavity The water container shall be a low form of 600 ml 20 oz beaker with an inside diameter of approx 8 5 cm 3 1 2 in and made of an electrically nonconductive material such as glass or...

Page 6: ...on hazard WARNING Never operate the oven until the following points are ensured A The door is tightly closed B The door brackets and hinges are not defective C The door packing is not damaged D The do...

Page 7: ...power HIGH MIX ROAST 300 F with 30 microwave power SLOW COOK 300 F for 4 hours no preheat BROIL 450 F preheat HELP GUIDE pad SENSOR REHEAT pad EASY MINUTE pad POPCORN pad AUTO DEFROST pad SENSOR COOK...

Page 8: ...ea turesareautomaticallyenabled when the door is opened and closed or the STOP CLEAR pad is pressed TOUCH CONTROL PANEL CAUTION DO NOT UNDER ANY CIRCUMSTANCES CUT OR REMOVE THE ROUND GROUNDING PRONG F...

Page 9: ...the following results The circuits to the turntable motor the cooling fan motor and the high voltage components are de energized the oven lamp remains on and the digital read out displays the time sti...

Page 10: ...the LOW MIX BAKE pad first Andthenprogramdesiredcookingtimebytouchingthe Number pads The LOW MIX BAKE pad is preprogrammed for 350 F with 10 microwave power while the HIGH MIX ROAST pad is preprogram...

Page 11: ...returned to the open position and the oven will go to the off condition The cooling fan will remain on until the oven has cooled AUTO DEFROST COOKING The AUTO DEFROST key is a special function key to...

Page 12: ...RY1 SECONDARY INTERLOCK SWITCH 120V 60Hz TTM FM COM RY1 E 5 E 4 E 3 E 2 E 1 F 3 F 2 F 1 RY3 RY2 PRIMARY INTERLOCK RELAY N O RY1 COM RY3 COM RY2 N O RY2 N O RY3 A 9 A 7 CM DM OL MAGNETRON TEMPERATURE F...

Page 13: ...omponents with potentials above 250V CONV THERMAL CUT OUT MONITOR SWITCH OVEN LAMP FAN MOTOR A 5 A 3 A 1 E 6 CONTROL UNIT DAMPER SWITCH THER MISTOR DOOR SENSING SWITCH AH SENSOR DAMPER MOTOR CONVECTIO...

Page 14: ...damper is in the open position except during convection cooking Damper position is set automatically by damper motor damper switch motor cam and damper shaft These components are operated by a signal...

Page 15: ...or an uninsulated tool while the power supply is connected When troubleshooting the microwave oven it is helpful to follow the Sequence of Operation in performing the checks Many of the possible caus...

Page 16: ...e Display does not operate properly when STOP CLEAR pad is touched The time of day should appear on the display with beep sound Oven lamp does not light with door opened Oven lamp does not light in co...

Page 17: ...e the cup of water in the oven Operate oven at POWER 10 HIGH selecting more than 60 seconds cook time Allow the water to heat for 60 seconds measuring with a stop watch second hand of a watch or the d...

Page 18: ...pply cord after the outer case is installed 8 Run the oven and check all functions F PRIMARY INTERLOCK SYSTEM TEST DOOR SENSING SWITCH 1 Disconnect the power supply cord and then remove outer case 2 O...

Page 19: ...meter should indicate a closed circuit When the monitor switch actuator is pushed by a screw driver through the lower latch hole on the front plate of the oven cavity with the door opened in this con...

Page 20: ...ater unit Check for restricted air flow to the heater unit through the vent holes of the oven cavity especially the heater duct and convection fan 5 Reconnect all leads removed from components during...

Page 21: ...sistance 68 F 20 C 86 F 30 C Approx 350k 155K 5 If the meter does not indicate above resistance replace the thermistor 6 Reconnect all leads removed from components during testing 7 Reinstall the oute...

Page 22: ...apacitor 4 Replace the Key unit 5 Reconnect all leads removed from components during testing 6 Re install the outer case cabinet 7 Reconnect the power supply cord after the outer case is installed 8 R...

Page 23: ...OP CLEAR pad is depressed first verify the flat ribbon cable is making good contact verify that the door sensing switch stop switch operates properly that is the contacts are closed when the door is c...

Page 24: ...ox 19 0V D C Convection motor RY6 Approx 19 0V D C Cooling fan motor 8 Disconnect the power supply cord and then remove outer case 9 Open the door and block it open 10 Discharge high voltage capacitor...

Page 25: ...the troubleshooting guide given below for repair STEPS OCCURRENCE CAUSE OR CORRECTION 1 The rated AC voltage is not present to power Check supply voltage and oven power cord terminal of CPU connecter...

Page 26: ...boiling bubbling If the oven does not turn off replace the AH sensor or check the control unit refer to explanation below TESTING METHOD FOR AH SENSOR AND OR CONTROL UNIT To determine if the sensor is...

Page 27: ...cord and then remove outer case 11 Open the door and block it open 12 Discharge high voltage capacitor 13 Disconnect the dummy resistor circuit from the sensor connector of control panel 14 Carry out...

Page 28: ...power is applied 5 Buzzer Circuit The buzzer is responds to signals from the LSI to emit noticingsounds keytouchsoundandcompletionsound 6 Temperature Measurement Circuit OVEN THERMISTOR The temperatur...

Page 29: ...ut to the grid of the Fluores cent Display 14 P54 OUT Oven lamp and turntable motor driving signal Square Waveform 60Hz To turn on and off the shut off relay RY1 The square waveform voltage is deliver...

Page 30: ...d to GND 27 RST IN Auto clear terminal Signal is input to reset the LSI to the initial state when power is applied Temporarily set to L level the moment power is applied at this time the LSI is reset...

Page 31: ...P23 Key strobe signal Signal applied to touch key section A pulse signal is input to P24 P27 terminal while one of G 9 line keys on key matrix is touched 45 P13 OUT Segment data signal Signal similar...

Page 32: ...with R50 1 Changing the resistance values results in that there is the same potential at both F 3 terminal of the absolute humidity sensor and AN7 terminal of the LSI The voltage of AN6 terminal will...

Page 33: ...d the oven itself is so short that the two can t be separated For those models check and repair all the controls sensor related ones included of the touch control panel while keeping it connected to t...

Page 34: ...2 Make sure that a definite click can be heard when the microwave oven door is unlatched Hold the door in a closed position with one hand then push the door open button with the other this causes the...

Page 35: ...ock it open 3 Discharge high voltage capacitor 4 Disconnect filament leads of transformer from the magnetron and capacitor 5 Disconnect high voltage lead of capacitor from the transformer 6 Disconnect...

Page 36: ...ve lock connector 5 Pull down on the positive lock connector CAUTION WHEN YOU CONNECTING THE POSITIVE LOCK CONNECTORS TO THE TERMINALS INSTALL THE POSITIVE LOCK SO THAT THE LEVER FACES YOU Figure C 2...

Page 37: ...ews holding the chassis support to the rear cabinet waveguide and control panel back plate 7 Remove the chassis support from the oven 8 Remove one 1 screw holding the magnetron air guide to the wavegu...

Page 38: ...igure the bracket by touching with the pliers 18 Remove the fan blade from the shaft of the fan motor by pulling and rotating the fan blade with your hand 19 Now the fan blade will be free CAUTION Do...

Page 39: ...goes through center of latch hole 2 Deviation of door alignment from horizontal line of cavity face plate is to be less than 1 0mm 3 Door is positioned with its face pressed toward cavity face plate...

Page 40: ...he eleven 11 screws holding the door panel to the door frame NOTE The one 1 screw of the twelve eleven 11 screws also holds the earth terminal of the door decoration to the door frame 6 Remove the doo...

Page 41: ...llways tight NOTE The neutral GRY wire must be connected to the terminal with N mark on the power supply cord OVEN LAMP SOCKET N O PNK N H G R Y R E D THERMISTOR 1 2 RED RED RED RED MONITOR FUSE FUSE...

Page 42: ...H DAMPER SWITCH OVEN THERMISTOR AH SENSOR OVEN LAMP TURNTABLE MOTOR RY6 RY2 D30 RY3 RY1 R31 4 7k R51 4 7k R62 27kF CF1 4 19MHz C70 330pF x 4 A B C C30 C50 C60 D3 D4 D7 Q1 2SB1238 Q4 DTA123ES Q3 KRA101...

Page 43: ...Technical Service 950 S Raymond Ave Pasadena CA 91105 800 353 2267...

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