Aiwa XR-EM20 Service Manual page 43

ADJUSTMENT (FRONT/DECK/TUNER/CD) - 4/8
<TUNER SECTION>
PATTERN SIDE
PART SIDE
L954
L955
L941
TC942
L905
L902
L904
L903
L901
(
1.CLOCK CHECK
Requirements
Measuring equipment: Frequency counter
Test point: TP1 (CLOCK), GND
(1) Adjust the reception frequency of the main unit to 1710KHz.
(2) Check that the test point frequency is 2160±0.045KHz.
2.VT ADJUSTMENT (FM)
Requirement
Measuring equipment: Digital multi-meter
Test point: TP4 (R962), GND
Adjustment point: L907
(1) Adjust the reception frequency of the main unit to 108.0MHz.
(2) Adjust L907 until the test point voltage (VT) is 7.0V±0.1V.
(3) Adjust the reception frequency of the main unit to 87.5MHz.
(4) Check that the test point (VT) voltage is more than 0.5V..
3.VT CHECK (MW)
Requirement
Measuring equipment: Digital multi-meter
Test point: TP4 (R962), GND
(1) Adjust the reception frequency of the main unit to 531KHz.
(2) Check that the test point (VT) voltage is more than 0.5V.
(3) Adjust the reception frequency of the main unit to 1602KHz.
(4) Check that the test point (VT) voltage is below 8.0V.
4.DC BALANCE CHECK
Requirement
Measuring equipment: Digital multi-meter
Test point: TP2, 3
(1) Adjust the reception frequency of the main unit to 98.0MHz.
(2) Check that the test point voltage difference between TP2 and TP3 is
0mV±500mV.
CN991
IC991
L942
IC801
L802
L907
L801
1211 8
16 1
^ TP8
(LCH)
TP9
*
(RCH)
&
(
TP1(24pin)
IC801
%
@
-43-
PATTERN SIDE
CN991
GND
TP4
TP2
R962
R815
TP3
FREQUENCY COUNTER
TP
GND
DIGITAL MULTIMETER
TP
GND
DIGITAL MULTIMETER
VT
GND
DIGITAL MULTIMETER
VT
GND
%^&
*(
!
@#
$
Hz
V
V
V