Sharp R-360EG Service Manual page 16

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. To discharge the high voltage capacitor, wait for 60 seconds.
4. If the monitor fuse is blown when the door is opened, check the secondary interlock relay, primary
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 SECONDARY INTER-
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-BA023WRK0, 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 CONTROL UNIT TEST
The control unit 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 control panel unit is divided into three units, CPU Unit, Key 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) To discharge high voltage capacitor, wait for 60 seconds.
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.
The following symptoms indicate a defective key unit.
a) When touching the pads, a certain pad produces no signal at all.
b) When touching a number pad, two figures or more are displayed.
c) When touching the pads, sometimes a pad produces no signal.
If the Key unit is defective, replace the key unit.
2. Control Unit
The following symptoms indicate a defective control unit. Before replacing the control unit, perform
the Key unit test (Procedure J) to determine if control unit is faulty.
TEST PROCEDURES
Screw Driver
LOCK RELAY, PRIMARY INTERLOCK SWITCH, DOOR SENSING SWITCH AND MONI-
TOR SWITCH FOR PROPER OPERATION.
COMPONENT TEST
WHT
RED
Monitor Switch
Primary
Interlock Switch
14
Ohmmeter