G: Monitor Switch Test; H: Blown Monitor Fuse Test - Sharp R-530EK-T Service Manual

R530EWT
2. PRIMARY INTERLOCK SYSTEM
2.1. DOOR SENSING SWITCH
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. Isolate the switch and connect the ohmmeter to the common (COM.) and normally open (NO) terminal of the switch. The meter should indicate an
open circuit with the door open and a closed circuit with the door closed. If improper operation is indicated, replace the door sensing switch.
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.
NOTE: If the door sensing switch contacts fail in the open position and the door is closed, the cooling fan, turntable and oven light will be activated by
RY1.
2.2. PRIMARY INTERLOCK RELAY (RY2)
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 two (2) wire leads from the male tab terminals of the Primary Interlock Relay. Check the state of the relay contacts using a ohmmeter.
The relay contacts should be open. If the relay contacts are closed, replace the circuit board entirely or the relay itself.
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.

[7] G: MONITOR SWITCH 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. Before performing this test, make sure that the secondary
interlock switch and the primary interlock relay are operat-
ing properly, according to the above Switch Test Proce-
dure. Disconnect the wire lead from the monitor switch
(COM) terminal. Check the monitor switch operation by
using the ohmmeter as follows. When the door is open, the
meter should indicate a closed circuit. When the monitor switch actuator is pushed by a screw driver through the lower latch hole on the front plate
of the oven cavity with the door opened (in this condition the plunger of the monitor switch is pushed in), the meter should indicate an open circuit.
If improper operation is indicated, the switch may be defective. After testing the monitor switch, reconnect the wire lead to the monitor switch
(COM) terminal and check the continuity of the monitor circuit.
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.

[8] H: BLOWN MONITOR 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. If the monitor fuse is blown when the door is opened, check the secondary interlock switch, primary interlock relay (RY2), relay (RY1) and monitor
switch according to the "TEST PROCEDURE" for those switches before replacing the blown monitor fuse.
CAUTION: BEFORE REPLACING A BLOWN MONITOR FUSE, TEST THE SECONDARY INTERLOCK SWITCH, PRIMARY INTERLOCK RELAY,
DOOR SENSING SWITCH AND MONITOR SWITCH FOR PROPER OPERATION.
If the monitor fuse is blown by improper switch operation, the monitor fuse and monitor switch must be replaced with "monitor fuse and monitor
switch assembly" part number FFS-BA033WRKZ or FFS-BA037WRKZ, even if the monitor switch operates normally. The monitor fuse and moni-
tor switch assembly is comprised of a 20 ampere fuse and switch.
5. Reconnect all leads removed from components during testing.
Red
Screw Driver
Secondary
Interlock Switch
8 – 3
White/ White
Ohmmeter
Monitor Switch