Onkyo CR-185 Service Manual

ADJUSTMENT PROCEDURES
It is not necessary to perform the adjustment of optical pickup.
This confirmation should be made when replacing the optical pickup.
1). Connect the oscilloscope to test points RF and VC.
Osilloscope
DC range
RF/Servo pc board
TPF) G
TP(VC) G
2). Turn the power switch on.
3). Load the test disc YEDS-18 on the tray and press the play button.
4). Confirm that the waveform on the oscilloscope is optimum eye _
pattern and optimum level as shown photo 1.
Optimum eye pattern means that shape "©" can be clearly
distinguished at the center of the waveform.
RF signal waveform
CH P1i36.2e4 A .Syps
CH1 445 .Sihz
CH S@uU cxasSGal
A=1.2V + 0.2 (Vp-p)
—~19—
V16571 / Druck 2
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 is
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.
e The time until music starts
becomes longer for STOP
+ DPLAY or automatic
Selection (Ke@ PPE buttons
pressed. (Normally takes
about 2 seconds.)
e Music does not start and
disc continues to rotate
for STOP —>DPLAY or
automatic selection (Ked
bt buttons pressed.)
e Sound is interrupted dur-
ing PLAY. Or time count-
er display stops progress-
ing.
e More poise during 2-axis
device operation.
The following is a simple adjustment method.
~ Simple Adjustment —
Note: Since exact adjustment cannot be performed, remem-
ber the positions of the controls before performing the
adjustment. If the positions after the simple adjust-
ment-are only a little different, return the controls to
the original position.
oscilloscope
(OC range)
Procedure:
Main board &
TP (FEO) a ey +
!
ck
TP (VC)
|
TP (TEO) Om- -?
. Keep the set horizontal.
If the set is not horizontal, this adjustment
[sao be performed due to the gravity against
the 2 axis device.
.
Insert
disc
(YEDS-18)
and
press
>
PLAY
button.
.
Connect
oscilloscope
to
RF/
Servo
board
TP
(FE).
. Adjust RV102 so that the waveform is as shown
in the figure below. (focus gain adjustment)
VOLT/DIV: 100mv
TIME/OIV: 2mS
100 mv
Ov
@
Incorrent
Examples
(DC
level
changes
more
than
on
adjusted
waveform)
low focus gain
VOLT/DIV: 100mv
TIME/DIV: 2mS
high
focus
gain
VOLT/ODIV.
100
TIME/DIV: 2mS
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/OIlV: IV
TIME/OIV: 2mS
@ Incorrect Examples (fundamental wave appears)
low tracking gain
VOLT/OIlV: IV
TIME/OIV: 2mS
high tracking gain
(higher fundamental wave than for low gain)
VOLT/OIv: 1V
TIME/OIV: 2mS
nA Ae A fw Ahab
med b dy y Vv verti
Adjustment Location: RF/ Servo board

Onkyo CR-185 Specifications

General

Brand	Onkyo
Model	CR-185
Category	Receiver
Language	English