Sony CDP-490 - Simple Adjustment

SECTION 4
DJUSTMENTS
=ss other-
ipedance.
cing the
RF) and
pattern.
can be
eform.
’
: 200mV
: $00nS
cing the
P (TEO)
4. Put the disc (YEDS-18) in and press > button.
5. Confirm that the traverse waveform is symmetrical
above and below.
6. After adjustment, remove the TP(ADJ), TP(TES) in
ground.
NOTE: Take sweep time as long as
possible to obtain best waveform.
\
A
7 OV
OV B B
A=B A=B
VOLT/DIV ; 1V
TIME/DIV : 1ms
RF PLL Free-run Frequency Check
Procedure:
frequency counter
aap
TP (PCK) ia
1. Connect the frequency counter to the test points
TP (PCK) and TP (GND).
2. Turn POWER switch on.
3. Put the disc (YEDS-18) in and press > button.
4. Confirm that the reading on the frequency counter
is locked at 4.3218 MHz.
Focus/Tracking Gain Adjustment
A frequency response analyzer is necessary in order
to perform this adjustment exactly.
However, this gain has a margine, so even if it is
slightly off, there is no problem. Therefore, this adjust-
ment is not recomended generally to be performed.
Focus/tracking gains determine the pick-up follow-up
(vertical and horizontal) relative to mechanical noise
and mechanical shock when the 2-axis device operate.
However, as these reciprocate, the adjustment is at
the point where both are satisfied.
@ When gain is raised, the noise when the 2-axis
device operates increases.
@ When gain is lowered, it is more susceptible to
mechanical shock and skipping occurs more easily.
@ When gain adjustment is off, the symptoms below
appear.
Symptoms m | Foc
@ The time until music starts
becomes longer for STOP
—>DPLAY or automatic
selection (td >>{ buttons)
pressed. (Normally takes
about 2 seconds.)
low or high
@Music does not start and
disc continues to rotate for
STOP >PDPLAY or auto- — low
matic selection (Ke DPI
buttons pressed.)
ae y t re |
@Sound is interrupted during
PLAY. Or time counter = low
display stops progressing.
@More noise during 2-axis
device operation.
The following is a simple adjustment method.
Simple Adjustment
Note: Since exact adjustment cannot be performed, remember the
positions of the controls before performing the adjustment.
If the positions after the simple adjustment are only a little
different, return the controls to the original position.
Procedure:
osciHoscope
(DC range)
BD board
_—_e"
TP (FEO)
TP (TEO)
TP (VC)
1. Keep the set flat.
If the set is not horizontal, this adjustment cannot be
performed due to the gravity against the 2 axis device.
2. Insert the disc (YEDS-18) and press > PLAY button.
3. Connect the oscilloscope to TP (FEO) and TP (VC).
4. Adjustment RV102 so that the waveform is as shown
in the picture below. (focus gain adjustment)
VOLT /DIV: 100mV
TIME/DIV: 2mS —
—— 100mV
i——— OV
@ Incorrect Examples (DC level is quite different from
the adjusted waveform) (below)
F VOLT “DIV: 100mV
low
focus
gain
TIME/DIV:
2mS
250mV
Ov
; VOLT/DIV: 100mVv
high focus gain TIMEDIV: 2mS
100mV
75mV
——- OV
5. Connect the oscilloscope to BD BOARD, TP (TEO).
6. Adjust RV101 so that the waveform is as shown in
the picture below. (tracking gain adjustment)
VOLT /DIV: 1V
TIME/DIV : 2mS
— ov
@ Incorrect Examples (fundamental wave appears)
low tracking gain
VOLT /DIV: 1V
TIME/DIV : 2mS
high tracking gain
(higher frequency of the fundamental wave than above)
VOLT DIV: 1V
TIME/DIV: 2mS
@ Adjustment Location :
MAIN BOARD (Component side)
TP (+5V)
TP
(EFM)
TP —o-
pe
TP
IC301
DG)
: TP ¢
~~, TP
(MDP)
TP (ADJ)'