..
“E
.
~....,.
CD PLAYER ADJUSTMENTS
Adjustment
Measuring
Short-
Input
Item
circuit
instrument
connection
location
‘(a) PLLVCO
Frequency counter
free-run
SHORT 1
—
Oscilloscope
(b) Tracking
L.P.F.
SHORT 1
—
balance
(c) Checking
the “eye” Oscilloscope
—
—
pattern
d. ADJUSTMENTS
( a ) PLL VCO free-run adjustment
(1) Test disc removed from the unit.
(2), Short-circuit points 1 on the printed-circuit board.
(3)
(4)
(5)
(6)
(b
(1)
(2)
(3)
(4)
(5)
(6)
(7)
(8)
‘ Connect a frequency counter to TP 5 ( PLL ) and
TP 4 ( GND ).
Switch ON the DC power ( 12.0 V ) ,’ ‘,.,..--: - “
(See component locations diagram at page 5)
Check the reading of the frequency counter
is 4.300 MHz -5.000 MHZ. -,-,
Cancel the short-circuiting of sho~t-circuitpoint 1
on the printed-circuit board. ‘“’
., ..,--
) Tracking balance adjustment
Short-circuit points 1 on the printed-circuit board .. ..- .:-,
Connect an oscilloscope to TP 1 (TE) and TP 2 (VC 2.5V).
Switch ON the DC power.
.“
Set the test disc.
PLAY switch push ON.
Cancel the short-circuiting of short-circuit point 1
on the printed-circuit board.
Adjust SVR302 so that the oscilloscope’s waveform is
symmetrical, as shown in the illustration.
Switch OFF the DC power.
( c ) Checking the eye pattern
. The adjustments (a) - (b) complete the adjustments of
the CD player.
Next, check the eye pattern waveform.
(1)
(2)
(3)
(4)
(5)
(6)
(7)
Switch ON the DC power.
Connect an oscilloscope to TP 3 ( RF) and
TP 2 (VC 2.5V ).
Load !he test disc.
PLAY switch push ON.
Check to be sure that the “ eye “ pattern is at the center
of waveform and that the diamond shape is clearly defined.
Press the STOP button.
Switch OFF the DC power.
..
-6-
Output
Adjust-
ment Adjustment value
connection
location
TP 5 (PLL)
—
4.300 MHz -5.000 MHz
TP 4 (GND)
TP1:TE
SVR302
Waveform symmetry
TP 2: VC2.5V A=B 1.5 Vp-p
Check be sure that the
TP3:f?F
“eye” pattern is at the
TP 2: VC2.5V
—
center of the waveform
and that the diamond
shaoe is clearlv defined
,.
,,. ,...
!-
.
!“-, .
L.P. F. “-
-1
1-
FREQUENCY
COUNTER
OSCILLOSCOPE
Ow
1.5vp-p
I vlolv
A-B
OSCILLOSCOPE
c
NM f XPANCKD
/
m
. . . .
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