Sharp R-310B Service Manual page 13

PROCEDURE
LETTER
G MONITOR RESISTOR TEST
CARRY OUT 3D CHECKS.
Disconnect the leads from the monitor resist. Using an ohmmeter and set on a low range. Check
between the terminals of the monitor resistor.
The resistance of monitor resistor is approx. 0.8 ohms.
If incorrect readings are obtained, replace the monitor resistor.
CARRY OUT 4R CHECKS.
H MOTOR WINDING TEST
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.
If incorrect readings are obtained, replace the motor.
CARRY OUT 4R CHECKS
I BLOWN FUSE F M8A
CARRY OUT 3D CHECKS.
1. If the fuse M8A is blown, there could be shorts or ground in electrical parts or wire harness.
Check them and replace the defective parts or repair the wire harness.
2. If the fuse M8A is blown when the door is opened, check the 2nd. latch switch, monitor switch and
monitor resistor.
If the fuse M8A is blown by incorrect door switching replace the defective switch(s) and the fuse
M8A.
3. If the fuse M8A is blown, there could be a short in the asymmetric rectifier or there could be a
ground in wire harness. A short in the asymmetric rectifier may have occured due to short or
ground in H.V. rectifier, magnetron, power 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 M8A WITH THE CORRECT VALUE REPLACEMENT
J NOISE FILTER TEST
CARRY OUT 3D CHECKS.
Disconnect the leads from the terminals of the noise
filter. Using an ohmmeter, check between the termi-
nals as described in the following table.
MEASURING POINT
Between N and L
Between terminal N and WHITE
Between terminal L and RED
If incorrect readings are obtained, replace the noise filter unit.
CARRY OUT 4R CHECKS.
TEST PROCEDURES
COMPONENT TEST
Table: Resistance of Motor
Motors
Approximately 390 Ω
Fan motor
Turntable motor Approximately 16.08 kΩ
INDICATION OF
OHMMETER
Open circuit
Short circuit
Short circuit
11
Resistance
L
N
L
L
Cy
Cx
Cx ± 20%
L (min)
600µH 0.068µF
R-310B
WHT
RED
Cy ± 20%
0.0022µF