Technics SL-PD647

SL-PD647 SL-PD647
Mi MEASUREMENTS AND ADJUSTMENTS
Warning:
This
product
uses
a
laser
diode.
Refer
to
caution
statements
on
page
2.
|
Measuring Instruments and Special Tools
Allen wrench (M2.0) (SZZP1101C)
Allen wrench (M1.27)
0.9mm clearance gauge (RZZ0297)
Filter
Lock paint (RZZOL01)
Test discs
Playability test disc (SZZP1054C)
Uneven test disc (SZZP1056C)
Musical program disc (ordinary)
Dual-beam oscilloscope with bandwidth of 30MHz
or better (with EXT. trigger and 1:1 probe).
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PREPARATION
. Remove the cabinet and front panel ass’y (refer to.
“disassembly instructions” Ref. No. 1, 2).
.
Set
the
power
switch
to
ON
and
press
the
open/
Best
ers
close
key
to close
the
loading
drawer.
. Press the play key and when the traverse deck
reaches it’s height position, set the power switch to
OFF.
. Remove.the tray ass’y (refer to “disassembly instruc-
tions” Ref. No. 3).
. Remove the clamp plate, yoke, magnet and clamper
(refer to “disassembly instructions” Ref. No. 8, 9).
.
Place
the
test
disc
and
secure
it
by
using
clamper
ass’y.
(Refer
to
Fig.
1)
(refer to “disassembly instructions” Ref. No. 9).
. Set the unit-in the test mode as follows:
(hold the FENg, and keys (3 keys) on
and set the power switch to ON.)
. Press the key and play the test disc.
. Follow the adjustment procedure.
Clamper ass’y
Test disc
Power switch
Adjusting
Procedure
Turn
table
| * If you have replaced the optical pickup, spindle
motor, or turntable, do the following adjustment:
Clearance gauge
0.9mm ree RZZ0297 )
UM, WUUMLEL MeLve7!
(1) TURNTABLE HEIGHT ADJUSTMENT
. Insert the 0.9mm clearance gauge (RZZ0297) between
the turntable and the loading base. (Refer to Fig. 2).
.
Tighten
the
turntable
retention
screw
with
the
1.27mm
allen
wrench.
. Connect the oscilloscope’s CH. 1 probe across
(+) and (—) terminal via a filter (Refer to Fig. 3).
Note: For the connection of oscilloscope’s CH. 1 probe
to servo P.C.B. on foil side, refer to fig. 2.
Oscilloscope setting: VOLT
Ss
Probe ;
(Oscilloscope) |
Input coupling
. Adjust oscilloscope’s DC zero balance.
. Switch the play power ON, and play the test disc
(SZZP1054C).
.
Measure
the
voltage
amplitude
of
the
signal
on
the
oscilloscope.
1G103 Servo P.C.B.
(AN8389SE1) (Soldered surface)
Fig. 3
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 voltage as 0V as possible. —
(2) MECHANICAL ADJUSTMENT
1. Connect the oscilloscope’s CH. 1 probe across .
(8) BEST EYE (PD BALANCE) ADJUSTMENT FOR TYPE A
1.
(+) and (GND) on the servo P.C.B.
(Refer to Fig. 1)
Oscilloscope setting: VOLT
Input coupling
. Switch the player power ON, and play track 7 on the
test disc (SZZP1056C).
(Playing any other track will prevent the HEX screws
from being accessed.)
. Leave the player in play mode and place it as shown |
Fig. 5.
. Alternately adjust the two HEX 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 Fig. 4)
. After completing the adjustment, lock the HEX
screws with lock paint (RZZOLO1).
Al en
wrenc
Range adjustable
with a allen wrench.
Fig. 5
Connect the oscilloscope’s CH. 1 probe across
(+) and (GND) on the servo P.C.B.
(Refer to Fig. 1)
Oscilloscope setting: VOLT
Input coupling
. Switch the player power ON, and play the 1kHz
(track 1) on the test disc (SZZP1054C).
. Adjust VR101 until the vertical fluctuation of RF
signal is minimized and the eye pattern is most
stretched. (Refer to Fig. 6)
CHECK OF PLAY OPERATION AFTER
ADJUSTMENT
Checking Skip Search
. Play an ordinary musical program disc.
. Press the skip button to check for normal skip search
operation (in both the forward’ and “reverse direc-
tions).
Checking Manual Search
. Play an ordinary musical program disc.
. Press the manual search button to check for smooth
manual search operations at either low or high speed
(in both the forward and reverse directions).
ANY
NI
Mechanical adjustment screws.
57
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* Most stretched eye pattern.
Fig. 6
Checking Playability
.
Play
the
0.7mm
black
dot
and
the
0.7mm
wedge
on
the
playability
test
disc
(SZZP1054C)
and
verify
that
no
sound
skip
or
noise
occurs.
.
Play
the
middie
tracks
of
the
uneven
test
disc
(SZZP1056C)
and
verify
that
no
sound
skip
or
noise
occurs.