Component Teardown and Testing
4-4
Magnetron Removal
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 wire leads from magnetron.
5. Remove nuts (4) securing magnetron to wave guide.
(See Figure 4-6)
6. Remove the magnetron with care so that the
magnetron antenna is not hit by any metal object
around the antenna. (See Figure 4-7)
Magnetron Testing
1. Continuity checks can indicate only an open
filament or a shorted magnetron. To diagnose an
open filament or shorted magnetron :
2. Isolate magnetron from the circuit by disconnecting
the wire 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.
When replacing the magnetron, be sure the R.F.
Anode Gasket is in place and mounting screws are
tightened securely.
To discharge the high voltage capacitor, 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.
Magnetron Mounting Nuts
(1 of 4 shown)
Magnetron Antenna
Gasket Plate
Cooling Fins
Figure 4-6. Magnetron Removal
Figure 4-7. Magnetron Components
Output Power of Magnetron
The output power of the magnetron can be measured by
performing a water temperature rise test.
Equipment needed:
* Two 1-liter cylindrical borosilicate glass vessel (Outside
diameter 190 mm).
* One glass thermometer with mercury column
1. Fill the one liter glass vessel with water.
2. Stir water in glass vessel with thermometer, and
record glass vessel’s temperature (“T1”, 10±1°C).
3. After moving the water into another glass vessel,
place it in the center of the cooking tray. Set the oven
to high power and operate for 47 seconds exactly.
(3 seconds included as a holding time of magnetron
oscillation:)
4. When heating is finished, stir the water again with the
thermometer and measure the temperature (“T2”).
5. Subtract T1 from T2. This will give you the water
temperature rise (T).
Check line voltage under load. Low voltage will
lower the magnetron output. Make all temperature
and time tests with accurate equipment.
Summary of Contents for E30MH65GPSA
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Page 32: ...Component Teardown and Testing 4 14 Notes ...
Page 33: ...Wiring Diagrams 5 1 Wiring Diagram ...
Page 34: ...Wiring Diagrams 5 2 Notes ...
Page 38: ...Parts List 6 4 Notes ...
