Technics SL-PC25

NS) Ed O45)
Measuring Instruments and Special Tools
* Servo gain adjuster (SZZP1017F or SZZP1094C—1)
Test discs
. Playability test disc (SZZP1054C or SZZP1014F)
. Uneven test disc (SZZP1056C)
. Black band test disc (SZZP1057C)
Normal disc
Dual-beam oscilloscope with bandwidth of 30 MHz or
better (with EXT trigger and 1 : 1 probe).
Audio frequency (AF) osillator
Comversion connector (SZZP1032F)
¥¥ WD = ¥
* *
Audio frequency oscillator
©OO9O
9 9
Servo gain adjuster
(SZ2ZP1017F) GND OSC
@® ON/OFF switch ®
iN
di GND®
Selector
Oscilloscope Oscilloscope connection
0_0 terminals
wn
ovo
TP2 TP3TPI
CHI rCH2 4
G JCH1 ©
(-12.1V) GND (+11.2V)
(Main) (Chassts) (Main)
(See page 15.)
Adjusting Procedure
* If you have replaced the optical pickup, spindle motor,
or turntable, do the following adjustment:
(1) TURNTABLE HEIGHT ADJUSTMENT
1. Insert the 0.9 mm clearance gauge (RZZ0297) between
the turntable and the loading base (see the figure at
right).
2. Tighten the turntable retention screw with the 1.27 mm
allen wrench.
3. Connect the oscilloscope’s CH. 1 probe across VR104's
(+) and VR106's (—) terminals via
a filter.
(Note:
A
voltage
of
2.5V
appears
at
the
V.
REF
terminal.
Take care not to short the player's chassis to the oscil-
loscope ground.)
Oscilloscope setting: VOLT.......... 50 mV
SWEEP oe has dds Tms.
Input coupling... DC
4. Adjust oscilloscope’s DC zero balance.
5. Switch the player power ON, and play the test disc
(SZZP1014F or SZZP1054C).
6. Measure the voltage amplitude of the signal on the
oscilloscope.
Note 1. If the measured amplitude is within a range of +/—
15 mV, the turntable height is correct. If it is outside
this range, adjust the turntable height by using the
clearance gauge as a pry.
If the amplitude exceeds +15 mV, lower turntable.
If the amplitude is below —15 mV, elevate the turntable.
Connection of servo gain adjuster (If you use SZZP1094C, refer to included operating instructions.)
Oscillator connection terminals
* Allen wrench (M2.0) (SZZP1101C)
* Allen wrench (M1.27)
* 0.9mm clearance gauge (RZZ0297)
* Filter
Perform adjustments depend on the part to be replaced
according to followings:
(1) Spindle MOtOr 0.0... cece ecccceeseetteseaeseeees Items 1,3 to 8
(2) TURN tal Ooi, cece sess sais od: dete, tosdédidicceeeeeesse es Items 1,3 to 8
(3) Optical PiCkUP....... ce cee ceccceeceessseeeenees Items 2 to 8
Conversion connector
(SZZP1032F)
To CN102
Turntable
Clearance gauge
(RZZ0297)
rosea sseee 0.9mm
OM dh
WS
Deerscsscssesses: W ts 33
Spindle motor
Note 2. If the measured amplitude greatly surpasses or
falls short of the range above, set VR105 at or around
the center, then try to adjust the height again. (Then
be sure to adjust the focus offset as well.)
Oscilloscope
eFilter for turntable height adjustment
Resistor: ERDS2TJ103 (10kQ)
Capacitor: ECQV1H104KV (0.1 uF) n0ee
2416