Read Sharp R-734 (serv.man4) Service Manual online
R-734 - 16
PROCEDURE
LETTER
COMPONENT TEST
G
BLOWN SPECIAL FUSE F1 20A
CARRY OUT 3D CHECKS.
If the special fuse F1 20A is blown, there is a shorts or grounds in electrical parts or wire harness. Check
them and replace the defective parts or repair the wire harness.
them and replace the defective parts or repair the wire harness.
CARRY OUT 4R CHECKS.
CAUTION:
Only replace
special
fuse
20A with
the correct value replacement.
H
BLOWN FUSE F2 F8A
CARRY OUT 3D CHECKS.
1. If the fuse F2 F8A is blown when the door is opened, check the monitored latch switch and monitor
switch.
2. If the fuse F2 F8A is blown by incorrect door switching replace the defective switch(es) and the fuse
F2 F8A.
3. If the fuse F2 F8A is blown, there could be shorts in the asymmetric rectifier or there is a ground in
wire harness. A short in the asymmetric rectifier may be occurred due to short or ground in H.V.
rectifier, magnetron, high voltage transformer or H.V. wire. Check them and replace the defective
parts or repair the wire harness.
rectifier, magnetron, high voltage transformer or H.V. wire. Check them and replace the defective
parts or repair the wire harness.
CARRY OUT 4R CHECKS.
CAUTION:
Only replace fuse
F2 F8A
with the correct value replacement.
CARRY OUT 3D CHECKS.
Disconnect the leads from the motor. Using an ohmmeter, check the resistance between the two
terminals as described in the table below.
terminals as described in the table below.
L (min)
Cx
±
20%
Cy
±
20%
1.0mH
0.22
µ
F
4700pF
MEASURING POINTS
INDICATION OF OHMMETER
Between N and L
Approx. 680 k
Ω
Between terminal N and WHITE
Short circuit
Between terminal L and RED
Short circuit
If incorrect readings are absorbed, replace the noise filter unit.
CARRY OUT 4R CHECKS.
I
NOISE FILTER TEST
CARRY OUT 3D CHECKS.
Disconnect the leads from the terminals of
noise filter.
Using an ohmmeter, check between the termi-
nals as described in the following table.
noise filter.
Using an ohmmeter, check between the termi-
nals as described in the following table.
J
MOTOR WINDING TEST
Table: Resistance of Motor
Motors
Resistance
Fan motor
Approximately
290
Ω
Turntable motor
Approximately 14.6 k
Ω
If incorrect readings are obtained, replace the motor.
CARRY OUT 4R CHECKS.
RED
WHT
L
L
R1
L
F2: F8A
R2
N
Cx
Cy
F1: 20A
R1: 10M ohm
±
20%
R2: 680k ohm
±
20%
TEST PROCEDURES
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