Service manual

31
DMO2420B
DMO2420R
DMO2420S
DOOR REPLACEMENT
1. Disconnect the power supply cord, and then remove
outer case.
2. Open the door and block it open.
3. Discharge high voltage capacitor.
If the door sensing switch, secondary interlock switch and
monitor switch do not operate properly due to a
misadjustment, the following adjustment should be made.
4. Loosen the two (2) screws holding latch hook to the oven
cavity front flange.
5. With door closed, adjust latch hook by moving it back and
forth, and up and down. In and out play of the door
allowed by the upper and lower position of the latch hook
should be less than 0.5mm. The vertical position of the
latch hook should be adjusted so that the door sensing
switch and secondary interlock switch are activated with
the door closed. The horizontal position of the latch hook
should be adjusted so that the plunger of the monitor
switch is pressed with the door closed.
6. Secure the screws with washers firmly.
7. Check the operation of all switches. If each switch has not
activated with the door closed, loosen screw and adjust
the latch hook position.
After adjustment, check the following.
1. In and out play of door remains less than 0.5mm when in
the latched position. First check upper position of latch
hook, pushing and pulling upper portion of door toward
the oven face. Then check lower portion of the latch hook,
pushing and pulling lower portion of the door toward the
oven face. Both results (play in the door) should be less
than 0.5mm.
2. The door sensing switch and secondary interlock switch
interrupt the circuit before the door can be opened.
3. Monitor switch contacts close when door is opened.
4. Re-install outer case and check for microwave leakage
around door with an approved microwave survey meter.
(Refer to Microwave Measurement Procedure.)
Figure C-3. Latch Switch Adjustments
REMOVAL
1. Disconnect the power supply cord.
2. Push the open button and open the door slightly.
3. Insert a putty knife (thickness of about 0.5mm) into the
gap between the choke cover and door frame as shown
in Figure C-4 to free engaging parts.
4. Pry the choke cover by inserting a putty knife as shown
in Figure C-4.
5. Release choke cover from door panel.
6. Now choke cover is free.
NOTE: When carrying out any repair to the door, do not
bend or warp the slit choke (tabs on the door
panelassembly) to prevent microwave leakage.
7. Release two (2) pins of door panel from two (2) holes of
upper and lower oven hinges by lifting up.
8. Now, door panel with door frame is free from oven cavity.
Figure C-4. Door Disassembly
9. Release the door panel from ten (10) tabs of door frame.
10.Remove the door panel from the door frame.
11.Now, door panel with sealer film is free.
12.Tear sealer film from door panel.
Door Sensing
Switch
Monitor Switch
Switch Lever
Secondary Interlock
Switch
Latch Heads
Door
Choke Cover
Door Frame
Putty Knife
monitor switches are in the lower position and the door
sensing switch is in the upper position.
2. Re-connect wire leads to each switch.
Refer to pictorial diagram.
3. Secure latch hook (with two (2) mounting screws) to oven
flange.
4. Make sure that the monitor switch is operating properly
and check continuity of the monitor circuit. Refer to
chapter "Test Procedure" and Adjustment procedure.
DOOR SENSING SWITCH/SECONDARY INTERLOCK SWITCH AND MONITOR SWITCH ADJUSTMENT