15
5. Alignment and Adjustments
5-4 High Voltage Capacitor
1.
Check continuity of the capacitor with the meter set at the highest resistance scale.
2.
Once the capacitor is charged, a normal capacitor shows continuity for a short time, and then indicates 9MΩ.
3.
A shorted capacitor will show continuous continuity.
4.
An open capacitor will show constant 9MΩ.
5.
Resistance between each terminal and chassis should read infinite.
5-5 High Voltage Diode
1.
Isolate the diode from the circuit by disconnecting its leads.
2.
With the ohm-meter set at the highest resistance scale, measure across the diode terminals. Reverse the meter
leads and read the resistance. A meter with 6V, 9V or higher voltage batteries should be used to check the front-to
back resistance of the diode (otherwise an infinite resistance may be read in both directions). The resistance of a
normal diode will be infinite in one direction and several hundred KΩ in the other direction.
5-6 Main Relay and Power Control RelayA
1.
The relays are located on the PCB Ass’y. Isolate them from the main circuit by disconnecting the leads.
2.
Operate the microwave oven with a water load in the oven. Set the power level set to high.
3.
Check continuity between terminals of the relays after the start pad is pressed.
5-7 Adjustment of Primary Switch, Door Sensing Switch and Monitor Switch
For continued protection against radiation hazard, replace parts in accordance with the wiring diagram
and be sure to use the correct part number for the following switches: Primary and secondary interlock
switches, and the interlock monitor switch (replace all together). Then follow the adjustment procedures
below. After repair and adjustment, be sure to check the continuity of all interlock switches and the interlock
monitor switch.
1.
When mounting Primary switch and Interlock Monitor
switch to Latch Body, consult the figure.
2.
No specific adjustment during installation of Primary switch
and Monitor switch to the latch body is necessary.
3.
When mounting the Latch Body to the oven assembly,
adjust the Latch Body by moving it so that the oven door
will not have any play in it. Check for play in the door by
pulling the door assembly. Make sure that the latch keys
move smoothly after adjustment is completed. Completely
tighten the screws holding the Latch Body to the oven
assembly.
4.
Reconnect to Monitor switch and check the continuity of
the monitor circuit and all latch switches again by following
the components test procedures.
5.
Confirm that the gap between the switch housing and
the switch actuator is no more than 0.5mm when door is
closed.
6.
Interlock Switch Replacement - When replacing faulty
switches, be sure switch mounting tabs are not bent,
broken or otherwise deficient in their ability to secure the
switches in place.
Primary Interlock Switch
Body Latch
Interlock Monitor
Switch
Door Sensing
Switch
Lever Door(B)
Door Open Door Closed
Primary Interlock switch
Monitor switch(COM-NC)
Door Sensing S/W
(Secondary interlock)
∞
0
∞
∞
0
∞
0
0
