Dacor PMOR3021B Service manual - Before Servicing

Manual is about: OVER THE RANGE MICROWAVE OVEN

Summary of PMOR3021B

  • Page 1

    1 pmor3021s pmor3021b pmor3021r s94m245p3021s pmor3021s pmor3021b pmor3021r over the range microwave oven models service manual this document has been published to be used for after sales service only. The contents are subject to change without notice. Dis tinctive appliances table of contents page ...

  • Page 2: Before Servicing

    2 pmor3021s pmor3021b pmor3021r precautions to be observed before and during servicing to avoid possible exposure to excessive microwave energy (a) do not operate or allow the oven to be operated with the door open. (b) make the following safety checks on all ovens to be serviced before activating t...

  • Page 3

    1 pmor3021s pmor3021b pmor3021r 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) inverter unit that includes high voltage capacitor, hi...

  • Page 4

    2 pmor3021s pmor3021b pmor3021r microwave measurement procedure a. Requirements: 1) microwave leakage limit (power density limit): the power density of microwave radiation emitted by a microwave oven should not exceed 1mw/cm 2 at any point 5cm or more from the external surface of the oven, measured ...

  • Page 5: Service Manual

    3 pmor3021s pmor3021b pmor3021r service manual microwave ovens pmor3021s/pmor3021b/pmor3021r foreword this manual has been prepared to provide dacor service personnel with operation and service information for the dacor micro- wave ovens, pmor3021s, pmor3021b and pmor3021r. It is recommended that se...

  • Page 6

    4 pmor3021s pmor3021b pmor3021r item description power requirements 120 volts / 12 amperes 60 hertz single phase, 3 wire grounded power output 1200 watts (iec test procedure) operating frequency of 2450mhz case dimensions width 29-15/16" height 17" depth 15- 9/16" cooking cavity dimensions width 22-...

  • Page 7

    5 pmor3021s pmor3021b pmor3021r 1 2 4 3 7 11 8 8 10 10 9 6 8 5 general information grounding instructions this oven is equipped with a three prong grounding plug. It must be plugged into a wall receptacle that is properly installed and grounded in accordance with the national electrical code and loc...

  • Page 8

    6 pmor3021s pmor3021b pmor3021r note: some one-touch cooking features such as "minute plus" are disabled after three minutes when the oven is not in use. These features are automatically enabled when the door is opened and closed or the stop/ clear pad is pressed. Pmor3021s.

  • Page 9

    7 pmor3021s pmor3021b pmor3021r operation description of operating sequence the following is a description of component functions during oven operation. Off condition closing the door activates the stop switch, primary interlock switch and secondary interlock switch. (in this condition, the monitor ...

  • Page 10

    8 pmor3021s pmor3021b pmor3021r ventilation methods hot air exhaust 1. Vertical venting for this venting method, hot air rising from the conventional range below is drawn in by the hood fan motor through the grease filters at the right and left sides of the base cover, up through the right and left ...

  • Page 11

    9 pmor3021s pmor3021b pmor3021r schematic note: condition of oven 1. Door closed 2. Cooking time programmed 3. Variable cooking control "high" 4. "start" pad touched figure o-2. Oven schematic-cooking condition figure o-1. Oven schematic-off condition schematic note: condition of oven 1. Door closed...

  • Page 12

    10 pmor3021s pmor3021b pmor3021r description and function of components monitor switch contacts. Caution: before replacing a blown monitor fuse test the stop switch, primary interlock switch, secondary inter- lock switch and monitor switch for proper operation. (refer to chap- ter "test procedure")....

  • Page 13

    11 pmor3021s pmor3021b pmor3021r troubleshooting guide never touch any part in the circuit with your hand 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 possi...

  • Page 14

    12 pmor3021s pmor3021b pmor3021r ck = check / re = replace possible case and defective parts problem test procedure condition off condition idle condition microwave cooking condition sensor cooking condition home fuse blows when power cord is plugged into wall receptacle. Monitor fuse blows when pow...

  • Page 15

    13 pmor3021s pmor3021b pmor3021r b inverter unit test test procedures procedure letter component test 1. Disconnect the power supply cord, and then remove outer case. 2. Open the door and block it open. 3. To discharge high voltage capacitor, wait for 60 seconds. 4. To test for an open filament, iso...

  • Page 16

    14 pmor3021s pmor3021b pmor3021r 1. Disconnect the power supply cord, and then remove outer case. 2. Open the door and block it open. 3. To discharge high voltage capacitor, wait for 60 seconds. 4. A continuity check across the thermal cut-out terminals should indicate a closed circuit unless the te...

  • Page 17

    15 pmor3021s pmor3021b pmor3021r test procedures procedure letter component test 4. Isolate the switch and connect the ohmmeter to the common (com.) and normally open (no) terminal of the switch. The meter should indicate an open circuit with the door open and a closed circuit with the door closed. ...

  • Page 18

    16 pmor3021s pmor3021b pmor3021r 6-pin connector of hood fan motor test procedures procedure letter component test 1. Disconnect the power supply cord, and then remove outer case. 2. Open the door and block it open. 3. To discharge high voltage capacitor, wait for 60 seconds. 4. A continuity check a...

  • Page 19

    17 pmor3021s pmor3021b pmor3021r test procedures procedure letter component test 1. Key unit. Note ; 1) check key unit ribbon connection before replacement. 2) re-install the hood intake duct r with seven (7) screws. 3) re-install the outer case (cabinet). 4) reconnect the power supply cord after th...

  • Page 20

    18 pmor3021s pmor3021b pmor3021r test procedures procedure letter component test schematic and place a jumper wire between the pins that correspond to the stop/clear pad making momentary contact. If the control unit responds by clearing with a beep the key unit is faulty and must be replaced. If the...

  • Page 21

    19 pmor3021s pmor3021b pmor3021r test procedures procedure letter component test (6) touch the “ start ” button. (7) the oven is in easy defrost cooking condition. (8) the oven will operate as follows. Menu 1st stage 2nd stage steaks/chops level time level time 0.5lbs 40% 57sec. 40% 22sec. (9) if im...

  • Page 22

    20 pmor3021s pmor3021b pmor3021r test procedures procedure letter component test 9) disconnect the power supply cord. 10) open the door and block it open. 11) to discharge high voltage capacitor, wait for 60 seconds. 12) reconnect all leads removed from components during testing. 13) re-install the ...

  • Page 23

    21 pmor3021s pmor3021b pmor3021r test procedures procedure letter component test (9) reconnect the oven to the power supply and check the sensor cook operation as follows: 9-1. Fill approximately 200 milliliters (7.2 oz) of tap water in a 1000 milliliter measuring cup. 9-2. Place the container on th...

  • Page 24

    22 pmor3021s pmor3021b pmor3021r test procedures procedure letter component test p noise filter test 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 transform...

  • Page 25

    23 pmor3021s pmor3021b pmor3021r touch control panel assembly outline of touch control panel 3) synchronizing signal circuit the power source synchronizing signal is available in order to compose a basic standard time in the clock circuit. It incorporates a very small error because it works on comme...

  • Page 26

    24 pmor3021s pmor3021b pmor3021r description of lsi lsi the i/o signal of the lsi is detailed in the following table. Pin no. Signal i/o description 1-2 vl2-vl1 in power source voltage input terminal. Standard voltage for lcd. 3-5 an7-an5 in terminal to change cooking input according to the model. B...

  • Page 27

    25 pmor3021s pmor3021b pmor3021r 25 p41 out terminal not used. 26 p40 in connected to gnd through the pull-down resistor. 27 reset in auto clear terminal. Signal is input to reset the lsi to the initial state when power is applied. 28 p71 out clock signal is output to a memory ic (ic3). 29 p70 out d...

  • Page 28

    26 pmor3021s pmor3021b pmor3021r pin no. Signal i/o description 48-72 seg24-seg0 out segment data signal. Connected to lcd. The relation between signals are as follows: lsi signal (pin no.) lcd (pin no.) lsi signal (pin no.) lcd (pin no.) seg 24 (48) ----------------- seg24 (29) seg 11 (61) --------...

  • Page 29

    27 pmor3021s pmor3021b pmor3021r humidity sensor circuit as the sensor cooking proceeds, the food is heated to generate moisture by which the resistance balance of the bridge circuit is deviated to increase the voltage available at an1 terminal of the lsi. Then the lsi observes that voltage at an1 t...

  • Page 30

    28 pmor3021s pmor3021b pmor3021r 1. Precautions for handling electronic components this unit uses cmos lsi in the integral part of the circuits. When handling these parts, the following precautions should be strictly followed. Cmos lsi have extremely high impedance at its input and output terminals....

  • Page 31

    29 pmor3021s pmor3021b pmor3021r sn-ag-cu precautions for using lead-free solder 1. Employing lead-free solder the "control unit pwb and inverter unit pwb" of this model employs lead-free solder. This is indicated by the "lf" symbol printed on the pwb and in the service manual. The suffix letter ind...

  • Page 32

    30 pmor3021s pmor3021b pmor3021r microwave ovens contain circuitry capable of producing very high voltage and current, contact with following parts may result in severe, possibly fatal, electric shock. (example) magnetron, inverter unit, high voltage harness etc.. Warning: avoid possible exposure to...

  • Page 33

    31 pmor3021s pmor3021b pmor3021r 4. Remove the three (3) screws holding the hood louver to the oven cavity front face plate. 5. Pull the hood louver from the oven cavity by pushing the right and left tabs of the hood louver to remove. 6. Now, the hood louver is free. Removal of oven from wall (two p...

  • Page 34

    32 pmor3021s pmor3021b pmor3021r 1. Disconnect the power supply cord and remove the oven from wall and remove outer case. (refer to procedure of "removal of oven from wall" and "outer case removal") 2. Open the door and block it open. 3. To discharge the high voltage capacitor, wait for 60 seconds. ...

  • Page 35

    33 pmor3021s pmor3021b pmor3021r rear view side view metal pieces may be produced. * do not touch the pliers to the coil of the fan motor because the coil may be cut or damaged. * do not disfigure the bracket by touching with the pliers. 2. Remove the fan blade from the shaft of the fan motor by pul...

  • Page 36

    34 pmor3021s pmor3021b pmor3021r 1. Disconnect the power supply cord. 2. Open the door and block it open. 3. To discharge the high voltage capacitor, wait for 60 seconds. 4. Remove the five (5) screws holding the bottom sush to the base cover. 5. Remove the three (3) screws holding the base cover to...

  • Page 37

    35 pmor3021s pmor3021b pmor3021r 1. Disconnect the power supply cord, remove the oven from wall, and remove outer case. (refer to procedure of "removal of oven from wall" and "outer case removal".) and proceed as follows. 2. Open the door and block it open. 3. To discharge the high voltage capacitor...

  • Page 38

    36 pmor3021s pmor3021b pmor3021r 1. Disconnect the power supply cord and remove the oven from wall and remove outer case. (refer to procedure of "removal of oven from wall" and "outer case removal") 2. Open the door and block it open. 3. To discharge the high voltage capacitor, wait for 60 seconds. ...

  • Page 39

    37 pmor3021s pmor3021b pmor3021r door assembly removal 1. Disconnect the power supply cord. 2. Open the door and block it open. 3. To discharge the high voltage capacitor, wait for 60 seconds. 4. Remove the three (3) screws holding the hood louver to the oven cavity front face plate. 5. Remove the h...

  • Page 40

    38 pmor3021s pmor3021b pmor3021r 9. Pry the choke cover by inserting a putty knife in order shown in figure c-3. 10.Now choke cover is free from door panel and door frame. Note: when carrying out any repair to the door, do not bend or warp the slit choke (tabs on the door panel assembly) to prevent ...

  • Page 41

    39 pmor3021s pmor3021b pmor3021r 6 4 5 1 2 3 6 4 5 1 2 3 a b c d e f g h a b c d e f g h figure s-1. Pictorial diagram high voltage components control unit power supply cord 120v 60hz 1 2 3 wht grn blk wht blu grn blk oven thermal cut-out fuse and holder fan motor oven lamp and socket to oven cavity...

  • Page 42

    40 pmor3021s pmor3021b pmor3021r 6 4 5 1 2 3 6 4 5 1 2 3 a b c d e f g h a b c d e f g h figure s-2b. Power unit circuit.

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    41 pmor3021s pmor3021b pmor3021r 6 4 5 1 2 3 6 4 5 1 2 3 a b c d e f g h a b c d e f g h figure s-3b. Lsi unit circuit.

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    42 pmor3021s pmor3021b pmor3021r figure s-4. Printed wiring board 6 4 5 1 2 3 6 4 5 1 2 3 a b c d e f g h a b c d e f g h.