Alpine Ai-NET CHA-1214 Service Manual page 17

CHA-1204
Judgments (7) Judgments (8)
Faulty play of
scratched disc
External CR fitter of
tracking servo system
is faulty
Unit does not play
External capacitor of
AN8806SB (IC 102) #13
Are the is faulty
outputs of : * R105 C123
wN6B2¥1 (10101) MN66271 (IC101) #44, prereset ag R16, 1R
eR EV? #45, #47, and #48 C16
*R109, 110, 111, 112 R131
+ #44---2.6V } CIOL, 102,130 EI3I
#45---15V TEBPF circuit between
#47--2.6V #25 and #23 of
#48---2.1V AN8806SB (IC102)
is faulty
*RI06 , 124
C107 , 108
Are the
outputs of
MN66271 (C101) #13,
MN66271 (IC101)
#14, and #15 is fauly
*#13—-0.1V
#14---4.9V
YES #15 --- 4.8V
Microprocessor (IC501)
is faulty
Drive unit or pickup
is fautty
Measurements
A. RF Signal Level Measurement
The main beam of the returning light is received by the photodiode and the output voltage is obtained by
current-voltage conversion of A+B+C+D.
1, Block Diagram
Sample player Oscilloscope
2. Measurement Method
(a). Connect the ground terminal of the oscilloscope VREF (AN8806SB (iC 102), PIN 20) and measure
the RF signal (of AN8806SB (IC 102), pin 7).
(b). Play the first track of the measurement disc A-BEX TCD-782.
(c). Read the peak-to-peak value of the waveform.
Specification: 0.5V +0.2
* When the value is outside of the specification (i.e., not good), check AN8806SB (IC 102), the pickup,
and R136/C120.
B. Jitter Measurement
The standard deviation of the pulse width when a trigger is applied to the rising edge of the 3T component of
the RF signal.
1. Block Diagram
Sample player Jitter meter
2. Measurement Method
(a). Connect the ground terminal of the jitter meter to VREF (AN8806SB (IC 102), PIN 20) and measure
the ARF signal (of AN8806SB (C102), pin 10).
(b). Play the first track of the A-BEX TCD-782 measurement disc.
(c). Read the indicated value of the jitter meter.
Specification: 25nS or less
* When the value is outside of the specification, check AN8806SB (IC 102), the pickup, and R136/C120.