Sharp R-15AT, Руководство по обслуживанию

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R-15AT
13
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.
Table: Resistance of Motor
Motors Resistance
Fan motor Approximately 219
Ω
Antenna motor Approximately 11 k
Ω
If incorrect readings are obtained, replace the motor.
CARRY OUT 4R CHECKS.
TEST PROCEDURES
PROCEDURE
LETTER COMPONENT TEST
I MOTOR WINDING TEST
CARRY OUT 3D CHECKS.
Disconnect the leads from the terminals of noise filter.
Using an ohmmeter, check between the terminals as described
in the following table.
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.
H NOISE FILTER TEST
J HIGH VOLTAGE FUSE F2 TST
CARRY OUT 3D CHECKS.
If the high voltage fuse F2 is blown, there could be a short in the high voltage rectifier or the magnetron.
Check them and replace the defective parts and the high voltage fuse.
CARRY OUT 4R CHECKS.
CAUTION: Only replace high voltage fuse with the correct value replacement.
The touch control panel consists of circuits including semiconductors such as LSI, ICs, etc. Therefore,
unlike conventional microwave ovens, proper maintenance can not 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 replacement is described according to the symptoms indicated.
1. Key Unit Note : Check key unit ribbon connection before replacement.
The following symptoms indicate a defective key unit. Replace the 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.
2. Control Panel
The following symptoms indicate a defective control unit. Before replacing the control unit.
perform the key unit test (Procedure L) to determine if control unit is faulty.
2-1 In connection with pads
a) When touching the pads, a certain group of pads do not produce a signal.
b) When touching the pads, no pads produce a signal.
2-2 In connection with indicators
a) At a certain digit, all or some segments do not light up.
b) At a certain digit, brightness is low.
c) Only one indicator does not light up.
d) The corresponding segments of all digits do not light up; or they continue to light up.
K TOUCH CONTROL PANEL ASSEMBLY TEST
F1: FUSE
F10A
N
L
DISCHARGE RESISTOR 680 k
Ω
1/2W
NOISE SUPPRESSION COIL
LINE BYPASS
CAPACITOR
0.0033
µ
F/ AC 250V
DISCHARGE
RESISTOR 10M
Ω
1/2W
WHT RED
LINE BYPASS
CAPACITOR
0.0033
µ
F/ AC 250V
LINE CROSS CAPACITOR 0.22
µ
F/ AC 250V
NOISE FILTER