Electrical Adjustment - Aiwa XR-TC80 Service Manual

ELECTRICAL ADJUSTMENT -1/6

<TUNER SECTION>
PART SIDE
L955
L954
L903
L904
1. CLOCK CHECK
Requirements
Measuring equipment: Frequency counter
Test point: TP1 (CLOCK), GND
1) Adjust the reception frequency of the main unit to 1,710 kHz.
2) Check that the test point frequency is 2160 ± 0.045 kHz.
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 108.0 MHz.
2) Adjust L907 until the test point voltage (VT) is 7.0 V ± 0.1 V.
3) Adjust the reception frequency of the main unit to 87.5 MHz.
4) Check that the test point (VT) voltage is about 1.5 V.
3. VT CHECK (AM)
Requirement
Measuring equipment: Digital multi-meter
Test point: TP4 (R962), GND
1) Adjust the reception frequency of the main unit to 530 kHz.
2) Check that the test point (VT) voltage is about 0.5 V.
3) Adjust the reception frequency of the main unit to 1710 kHz.
4) Check that the test point (VT) voltage is below 9.0 V.
4. DC BALANCE CHECK
Requirement
Measuring equipment: Digital multi-meter
Test point: TP2, 3
1) Adjust the reception frequency of the main unit to 98.0 MHz.
2) Check that the test point voltage difference between TP2 and TP3 is 0 mV ± 500 mV.
CN991
IC991
IC801
L802
L907
PATTERN SIDE
CN991
6 TP8 2pin
TP9 1pin
7
TP1 (24pin)
IC801
5
2
-34-
GND 12pin
TP4
TP2
R962
R815
TP3
TP
GND
TP
GND
VT
GND
VT
GND
1 2 3
6 7
5
5
6 7
1
2 3
4
FREQUENCY COUNTER
Hz
DIGITAL MULTIMETER
V
DIGITAL MULTIMETER
V
DIGITAL MULTIMETER
V