Adjustment (Tuner / Deck / Cd / Fl) - Aiwa XR-EM70 Service Manual

ADJUSTMENT (TUNER / DECK / CD / FL)

<TUNER SECTION>
PWB TUNER
PATTERN SIDE
1. VT Adjustment (LW)
Requirement
Measuring Device: Digital Multimeter
Test Point: VT, GND
Adjustment Point: L942
(1) Adjust the reception frequency of the set to 144 kHz.
(2) Adjust L942 until the test point voltage (VT) is 1.3 V ± 0.05 V.
(3) Adjust the reception frequency of the set to 290 kHz.
(4) Check that the test point (VT) voltage is below 8 V.
2. VT Check (MW)
Requirement
Measuring Device: Digital Multimeter
Test Point: VT, GND
(1) Adjust the reception frequency of the set to 1602 kHz.
(2) Check that the test point voltage is below 8 V.
(3) Adjust the reception frequency of the set to 531 kHz.
(4) Check that the test point voltage is above 0.6 V.
3. CLOCK Check
Requirement
Measuring Device: Frequency Counter
Test Point: CLOCK, GND
(1) Change to MW and adjust the reception frequency of the set to 1602 kHz.
(2) Check that the test point (CLOCK) frequency is 2052 kHz ± 45 Hz.
4. VT Adjustment (FM)
Requirement
Measuring Device: Digital Multimeter
Test Point: VT, GND
Adjustment Point: L907
(1) Adjust the reception frequency of the set to 108.0 kHz.
(2) Adjust L907 until the test point voltage (VT) is 7 V ± 0.05V.
(3) Adjust the reception frequency of the set to 87.5 MHz.
(4) Check that the test point voltage is above 0.5 V.
VT
JW970
IC991
IC801
24
CN991
4
12 11
CLK
Rch
Lch
Lch
PARTS SIDE
L801
CN991
GND
– 33 –
L908
L802
L942
TC942
DIGITAL MULTIMETER
VT
GND
DIGITAL MULTIMETER
VT
GND
FREQUENCY COUNTER
CLOCK
GND
DIGITAL MULTIMETER
VT
GND
1 2 4
4
9
L902
L901
1
L941
7
L951 6
5
1 2 3 4
6
5 7 9
6
5 7 9
3
V
V
Hz
V