Onkyo DX-C909 Service Manual

JSTMENT PROCEDURES
ecessary to perform the adjustment of optical pickup.
irmation should be made when replacing the optical pickup.
sct the oscilloscope to test points RF and VC.
Osilloscope
DC range
m pcb
GO ©)
© ©)
he power switch on.
the test disc YEDS-18 on the tray and press the play button.
rm that the waveform on the oscilloscope is optimum eye
n and optimum level as shown photo 1.
um eye pattern means that shape ">" can be clearly
vished at the center of the waveform.
ci «| P136.2
-19-
.{ @Disc table opens shortly
hi h
REFERENCE
Focus/Tracking Gain Adjustment
A frequency response analyzer is necessary in
order to perform this adjustment exactly.
However, this gain has a margin, so even if it 1s
slightly off, there is no problem. Therefore, do not
perform this adjustment.
Focus/tracking gain determines the pick-up follow-
up (vertical and horizontal) relative to mechanical
noise and mechanical shock when the 2-axis device
operate.
However, as these reciprocate, the adjustment is at
the point where both are satisfied.
@ When gain is raised, the noise when the 2-axis
device operates increases.
@ When gain is lowered, it is more susceptible to
mechanical shock and skipping occurs more easily.
@ When gain adjustment is off, the symptoms below
appear.
symp | roo | retina
e The time until music starts
becomes longer for STOP
+> OPLAY or automatic
selection (Ke Pi buttons
pressed. (Normally takes
about 2 seconds.)
low or high
@ Music does not start and
disc continues to rotate
for STOP >DPLAY ar
automatic selection ( Ke
bhi buttons pressed.)
@ Sound is interrupted dur-
ing PLAY. Or time count- _ low
er display stops progress-
ing.
e More poise during 2-axis high high
device operation.
The following is a simple adjustment method.
- Simple Adjustment —
Note: Since exact adjustment cannot be performed, remem-
ber the positions of the controis before performing the
adjustment. {f the positions after the simple adjust-
ment are only a little different, return the controls to
the original position.
oscilloscope
{DC range}
Procedure: g
main board C)
TP {FEO} Oo OO +
—
| l { :
TP {TEO) Ow- -7
1. Keep the set horizontal.
If the set is not horizontal, this adjustment
cannot be performed due to the gravity against
the 2 axis device.
be
Insert disc (YEDS-18)} and press PLAY button.
Connect oscilloscope to RF/ Servo board TP(FE).
Bow
Adjust RV102 so that the waveform is as shown
in the figure below. (focus gain adjustment)
VOLT/DIV: 100 mv
TIME/DOIV: 2mS
@ Incorrent Examples (DC level changes more than
on adjusted waveform)
low focus gain
TIME/OIV: 2mS
a 250 mv
—oOV
° high focus gain
VOLT/DI¥.. 100
TiIME/Div: 2mS
VOLT/DIV: 100 mV
5. Connect oscilloscope to RF/ Servo board TP (TE).
6. Adjust RV101 so that the waveform is as shown in
the figure below. (tracking gain adjustment)
VOLT/DIV.
TIME/DIV:
B—ov
® Incorrect Examples (fundamental wave appears)
low tracking gain
VOLT/OIV.
TIME/DIV:
f—ov
high tracking gain
{higher fundamentel wave than for low gain)
VOLT/DIV
TIME/DIV.
— Ov
fydad Vvyisenis ts
Adjustment Location: RF/ Servo board
Te ve
og
RVIO2
FO GAIN O 4
O
RVIGL
TR GAIN
_ 20-

Onkyo DX-C909 Specifications

General

Brand	Onkyo
Model	DX-C909
Category	CD Player
Language	English