Dacor DCM24B Service Manual page 24

PROCEDURE
LETTER
R RELAY 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 transformer.
5. Ensure that these leads remain isolated from other components and oven chassis by using insulation
tape.
6. After that procedure, re-connect the power supply cord.
7. Remove the outer case and check voltage between Pin Nos. 7 and 9 of the 9 pin connector (A) on
the control unit with an A.C. voltmeter. The meter should indicate 120 volts, if not check oven circuit.
Shut-off, Cook and Heater Relays Test
These relays are operated by D.C. voltage
Check voltage at the relay coil with a D.C. voltmeter during the microwave cooking operation or
convection cooking condition.
DC . voltage indicated ............... Defective relay.
DC. voltage not indicated ........... Check diode which is connected to the relay coil. If diode is good,
RELAY SYMBOL
RY1
RY2 (COOK)
RY3 (HEATER)
RY4
RY5
RY6
8. Disconnect the power supply cord, and then remove outer case.
9. Open the door and block it open.
10.Discharge high voltage capacitor.
11.Reconnect all leads removed from components during testing.
12.Re-install the outer case (cabinet).
13.Reconnect the power supply cord after the outer case is installed.
14.Run the oven and check all functions.
S AUTO DEFROST TEST
WARNING : The oven should be fully assembled before following procedure.
(1) Place one cup of water in the center of the turntable tray in the oven cavity.
(2) Close the door, touch the AUTO DEFROST pad twice and touch the number pad 5. And then touch
the start pad.
(3) The oven is in Auto Defrost cooking condition.
(4) The oven will operate as follows
WEIGHT
0.5lbs
(5) If improper operation is indicated, the control unit is probably defective and should be checked.
T PROCEDURES TO BE TAKEN WHEN THE FOIL PATTERN ON THE PRINTED WIRING BOARD
(PWB) IS OPEN.
To protect the electronic circuits, this model is provided with a fine foil pattern added to the primary on
the PWB, this foil pattern acts as a fuse.
1. Foil pattern check and repairs.
1) Disconnect the power supply cord, and then remove outer case.
2) Open the door and block it open.
3) Discharge high voltage capacitor.
TEST PROCEDURES
control unit is defective.
OPERATIONAL VOLTAGE
Approx. 19.0V D.C.
Approx. 18.0V D.C.
Approx. 18.0V D.C.
Approx. 19.0V D.C.
Approx. 19.0V D.C.
Approx. 19.0V D.C.
1ST STAGE 2ND STAGE
LEVEL TIME LEVEL
70% 47sec. 0%
21
COMPONENT TEST
CONNECTED COMPONENTS
Oven lamp / Turntable motor
Power transformer
Heating element
Damper motor
Convection motor
Cooling fan motor
3RD STAGE
TIME LEVEL TIME
52sec. 50% 32sec.
DCM24B
DCM24R
DCM24S
4TH STAGE
LEVEL TIME
30% 40sec.