Sharp CD-JX20X(GY) Service Manual page 17

Since the adjusting procedure differs from that described in " ADJUSTMENT PROCEDURES OF AUDIO PRODUCTS" , refer to
the Service Manual.
All the semivariable resistors must be set in the mechanical center position
Test Stage
Set TEST MODE 0. and move the oickuo to the center
Set Test MODE 1 (make sure that the laser lamp Ilghts)
heard.)
Set TEST MODE 3 (Spin servo is turned on. and the disc rotates)
Tracking error balance adj
I
Set TEST MODE 4 (Tracklna servo IS turned on.)
Check agaln the HF signal waveform.
Set TEST MODE 5, and make sure that track No. and time are displayed.
Stick black tape on the disc, and play that section (Fig. 22-l). (Any mode other than the test mode is acceptable.)
Focus offset adj, VR700
Tracking offset adj.
1 Adjust to obtain vertically symmetrical waveform (Fig. 21-I) with respect to reference DC level. The reference level is l/ZVcc
[Amplitude of 0.5 to 1.5 Vpp)
properly without noise (track jump noise) and free from skips and pauses.
Connect the trigger to pin 14 (HFOK) of CNP700.
Trigger the coupling at DC and (-) slope. Observe the waveform in the normal trigger mode.
properly without noise (track jump noise).
(Reference) When the noise element of the error waveform is large and unclear, observe the waveform through the low-pass
filter (Fig. 22-3).
Figure 21-l
Value/Adjusting Method Instrument Connecl~on
_ _
' 1 (See Fig. 21-l)
Pin 6 (i/ZVcc) and pin 4 (TGI)
of TP751
i
circuit is used.)
'4 (Fig. 22-Z) Pin 6 (ll2Vcc) and Din 1 (FGII
o f T P 7 5 1
'6
Pin 6 (1/2Vcc) and pin 4 (TGI)
Figure 21-2
Figure 22-1
' 5
FOCUS
O F F S E T
Figure 22-2
P I C K U P
TP75 1
TRACK IN
T R A C K I N FOCUS
G A I N
O F F S E T G A I N
Figure 22-4 ADJUSTMENT POINTS
Figure 22-3