Sharp R-501CK Service Manual page 16

R - 5 0 1 C K
R- 501CW
PROCEDURE
LETTER
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.
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 primary interlock relay, secondary
interlock switch 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 PRIMARY INTERLOCK
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-BA016/KIT, even if the
monitor switch operates normally. The monitor fuse and monitor switch assembly is comprised of a 20
ampere fuse and 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.
I TOUCH CONTROL PANEL ASSEMBLY TEST
The touch control panel consists of circuits including semiconductors such as LSI, ICs, etc. Therefore,
unlike conventional microwave ovens, proper maintenance cannot be performed with only a voltmeter and
ohmmeter.
In this service manual, the touch control panel assembly is divided into two units, Control Unit and Key
Unit, and also the Control Unit is divided into two units, LSI Unit and Power Unit, and troubleshooting by
unit replacement is described according to the symptoms indicated.
Before testing,
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 the leads to the primary of the power transformer.
5) Ensure that these leads remain isolated from other components and oven chassis by using
insulation tape.
1. Key Unit.
NOTE ;
1) Check Key unit ribbon connection before replacement.
2) Reconnect all leads removed from components during testing.
3) Re-install the outer case (cabinet).
4) Reconnect the power supply cord after the outer case is installed.
5) Run the oven and check all functions.
The following symptoms indicate a defective key unit.
a) When touching the pads, a certain pad produces no signal at all.
TEST PROCEDURES
Secondary Interlock Switch
RELAY, SECONDARY INTERLOCK SWITCH, DOOR SENSING SWITCH AND MONITOR
SWITCH FOR PROPER OPERATION.
COMPONENT TEST
Screw Driver
RED
WHT/WHT
14
Monitor
Switch
Ohmmeter