Technics SL-PS900 - Measurements and Adjustments; Preparation and Adjustment Procedures

SL-PS900 SL-PS900 |
Mi MEASUREMENTS AND ADJUSTMENTS * Adjustment procedure
Warning:
This
product
uses
a
laser
diode.
Refer
to
caution
statements
on
page
3.
Measuring
Instruments
and
Special
Tools
* Test discs Dual-beam oscilloscope with bandwith of 30MHz or
. Playability test disc (SZZP1054C) better (with EXT. trigger and 1: 1 probe).
Caution:
During
adjustment,
never
connect
CH-2
probe’s
GND
to
any
place
for
it
may
short
Vref
line.
(Connect
CH-1
probe’s GND
to
specified
TP.
described
in
each
section.)
1
2. Uneven test disc (SZZP1056C) Allen wrench (M2.0) (SZZP1101C)
* Normal disc (Ordinary musical program disc) Allen wrench (M1.27)
* Filter (Refer to Fig. 1) Lock paint (RZZOL01)
0.9mm clearance gauge (RZZ0297)
PREPARATION
1. Remove the cabinet and front panel ass’y (See Ref.
No. 1, 2 of the disassembly instructions).
2. Remove the clamp plate ass’y, magnet and clamper
(see Ref. No. 10, 11 of the same).
3. Remove the rotation lever, disc tray ass’y and drive
plate (see Ref. No. 12, 14, 15 of the same).
4. Attach the front panel to the unit.
5. Turn the pulley gear fully in the direction of arrow
until traverse unit comes up.
6. Place the test disc and fix it by using the magnet &
clamper.
Pulley
gear Adjusting Procedure
* If you have replaced the optical pickup, spindle
motor, or turntable, do the following adjustment: Turn table
Clearance gauge
0.9mm
(RZZ0297 )
ee eee
Test
disc (S751)
(1) TURNTABLE HEIGHT ADJUSTMENT
1. Insert the 0.9mm _ clearance gauge (RZZ0297)
between the turntable and the loading base. (Refer
to right figure)
|
Spindle motor
7, Power switch to ON. . } 2. Tighten the turntable retention screw with the
8. While pushing the open/close det. switch (S751) in 427mm alien wrench.
the direction of arrow, push the play switch. 3. Connect the oscilloscope’s CH. 1 probe across
Power Magnet & clamper (+) and (—) terminal via a filter.
switch Note: For the connection of oscilloscope’s CH. 1 Filter
probe to servo P.C.B. on foil side.
(Refer to Fig. 1)
Probe
¢
Adjustment
points
Oscilloscope
setting:
alle
sipiveatnanvacts
500
mV
(Oscilloscope)
secheesseaueateess
5ms.
Input
coupling......DC
8
80n88h088
4.
Adjust
oscilloscope’s
DC
zero
balance.
Derr
5.
Switch
the
play
power
ON,
and
play
the test
disc
Servo
P.C.B.
e
SERVO
P.C.B.
(SZZP1054C).
(Soldered
surface)
6.
Measure
the
voitage
amplitude
of
the
signal
on
the
oscilloscope.
Fig.
1
7. Adjust the height until the voltage is 0+1.0V.
If the voltage exceeds +1.0V, lower turntable.
If the voltage is below —1.0V, elevate the turn table.
Note: Mesure the voitage as OV as possible.
Optical pickup
(2) MECHANICAL ADJUSTMENT
1. Connect the oscilloscope’s CH. 1 probe across
(RF) and (GND) on the servo P.C.B.
(Refer to Fig. 3 on page 15)
Fig. 1
Oscilloscope setting: VOLT ...........000...- 200mvV
ew Sis Plel
bbe F ee LIV YAAK AR AAAI A
Input coupling.....AC PAUINes'eseceecenee:
Fig. 3 2. Switch the player power ON, and play track 7 on the
AAV OIO OOOOO OO)
ANY
test disc (SZZP1056C).
(Playing any other track will prevent, the HEX screws
Range
from
being
accessed.)
VVIVVIVVIVVIV
VV
VV
VI
adjustable
3.
Leave
the
player
in
play
mode
and
place
the
player
|
VOOR
OOOO)
with
a
allen
as
shown
Fig.
2
on
page
15.
AAAAARARAARARAAD
ON a i nT a Ok te ines
wrench
4. Alternately adjust the two mechanical adjusting
Screws with the 2.0mm allen wrench (SZZP1101C)
until the vertical fluctuation of RF signal is
minimized and the eye pattern is most stretched.
(Refer to right figure)
5. After completing the adjustment, lock the HEX
Fig.
2
Screws
with
lock
paint
(RZZOLO1).
% Most stretched eye pattern.
ae
5
2
—
16
—