Technics SL-PJ28 - Page 7

Mi MEASUREMENTS AND ADJUSTMENTS
Warning: This product uses a laser diode.
Caution:
Refer to caution statements on page 3.
During adjustment, never connect CH-2 probe's GND to any place for it may short V-Ref. line.
(Connect CH-1 probe’s GND to specified TP. described in each section.)
Measuring Instruments and Special Tools
*
1
2.
*
*
Test discs
. Playability test disc (SZZP1054C)
. Uneven test disc (SZZP1056C)
Musical program disc (ordinary)
Extension cable kit (RFKZ0009)
(1) MECHANICAL ADJUSTMENT
«When the traverse deck Is replaced, making ad-
Justments is not necessary. (The traverse deck ass'y
is already adjusted.)
«Make adjustments to improve playability if the
bad
traverse deck has not been replaced.
1.
Connect the oscilloscope’s CH. 1 probe across
(RF) (+) and (V-Ref.) (—) on the
servo P.C.B.
Oscilloscope setting: VOLT
SWEEP...
Input coupling "AC
. Switch the player power ON, and play track 19 on
the test disc (SZZP1056C).
(Playing any other track is selected,
screws Can not be accessed.)
the HEX
. Leave the player in play mode, and place the traverse
deck as shown Ref. No. 18 on page 10.
Alternately adjust the two mechanical adjusting
screws with the 2.0mm allen wrench (SZZP1101C)
until the vertical fluctuation of RF signal is mini-
mized and the eye pattern is most stretched.
(Refer to Fig. 2 on page 13)
After completing the adjustment,
screws with lock paint (RZZOL01).
lock the HEX
(2) BEST EYE (PD BALANCE) ADJUSTMENT
1.
2.
3.
Connect the oscilloscope’s CH. 1 probe across
(RF) (+) and (V-Ref.) (—) on the
servo P.C.B.
Oscilloscope setting: VOLT
SWEEP...
Input coupling ‘AG
Switch the player power ON, and play the 1kHz
(track 1) on the test disc (SZZP1054C).
Adjust VR701 until the vertical fluctuation of RF
signal is minimized and the eye pattern is most
Stretched. (Refer to Fig. 1 on page 13)
* Dual-beam oscilloscope with bandwidth of 30MHz
or better (with EXT. trigger and 1: 1 probe).
* Allen wrench (M2.0) (SZZP1101C)
* Lock paint (RZZOL01)
ree:
ANY RRNA RAN
WAKA
AKA
AKADAD.
NRX AAR ARN
‘eee
|
Va
iusstevedisaes
Seen
LY
X}
™ Most stretched eye pattern.
AS
NW susan
NN
VITRO
eee ee
wh Aw hs seve