Dacor DCM24B, Service Manual, Page: 20 / 43

17
DCM24B
DCM24R
DCM24S
TEST PROCEDURES
PROCEDURE
LETTER
COMPONENT TEST
I MAGNETRON TEMPERATURE FUSE 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. A continuity check across the temperature fuse terminals should indicate a closed circuit unless the
temperature of the magnetron reaches approximately 302˚F(150˚C). An open temperature fuse
indicates overheating of the magnetron. Check for restricted air flow to the magnetron, especially the
cooling duct and cooling fan.
5. Reconnect all leads removed from components during testing.
6. Reinstall the outer case (cabinet).
7. Reconnect the power supply cord after the outer case is installed.
8. Run the oven and check all functions.
CAUTION: IF THE TEMPERATURE FUSE INDICATES AN OPEN CIRCUIT AT ROOM TEMPERA-
TURE, REPLACE TEMPERATURE FUSE.
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. A continuity check across the thermal cut-out terminals should indicate a closed circuit unless the
temperature of the thermal cut-out reaches approximately 302˚F(150˚C). The thermal cut-out resets
automatically at approximately 266˚F(130˚C). If thermal cut-out has opened under normal condition,
replace the same item as in the parts list.
An open thermal cut-out indicates overheating of the heater 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 testing.
6. Reinstall the outer case (cabinet).
7. Reconnect the power supply cord after the outer case is installed.
8. Run the oven and check all functions.
CAUTION: IF THE THERMAL CUT-OUT INDICATES AN OPEN CIRCUIT AT ROOM TEMPERATURE,
REPLACE THERMAL CUT-OUT.
K HEATING ELEMENT 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. Make sure the heating element is fully cooled and test as follows;
a. Disconnect wire leads from the heating element and measure the resistance with an ohmmeter.
On the R x 1 scale, the resistance between the heating element terminals should be approximately
10.2
Ω
.
b. Disconnect wire leads from the heating element and measure the insulation resistance with 500V
- 100M
Ω
insulation resistance meter. The insulation resistance between heating element terminal
and cavity should be more than 0.5M
Ω
.
5. If the meter does not indicate above resistance, replace the thermistor
6. Reconnect all leads removed from components during testing.
7. Reinstall the outer case (cabinet).
8. Reconnect the power supply cord after the outer case is installed.
9. Run the oven and check all functions.
5. Reconnect all leads removed from components during testing.
6. Reinstall the outer case (cabinet).
7. Reconnect the power supply cord after the outer case is installed.
8. Run the oven and check all functions.
J CONV. THERMAL CUT-OUT TEST