Sharp R-21JV-F Service Manual page 16

R-21HT-F
R-21JV-F
PROCEDURE
LETTER
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-BA015WRK0, 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 NOISE FILTER 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. Disconnect the lead wires from the terminal the noise
filter. Using an ohmmeter, check between the terminals
as described in the following table. If incorrect reading are
obtained, replace the noise filter.
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.
MEASURING POINT
Between N and L
Between terminal N and WHITE
Between terminal L and RED
J 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 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
6) After that procedure, re-connect the power supply cord.
TEST PROCEDURES
RELAY, SECONDARY INTERLOCK SWITCH, DOOR SENSING SWITCH AND MONITOR
SWITCH FOR PROPER OPERATION.
tape.
COMPONENT TEST
N
WHITE
INDICATION OF OHMMETER
Open circuit
Short circuit
Short circuit
14
LINE CROSS CAPACITOR 0.22 F AC250V
NOISE SUPPRESSION COIL
LINE BYPASS LINE BYPASS
CAPACITOR CAPACITOR
0.003300 F / AC 125V 0.003300 F / AC 125V
L
FUSE
20A
RED