Onkyo DX-6630 User manual

DX-6630
ONKYO. SERVICE MANUAL
COMPACT DISC PLAYER
MODEL DX-6630
Black and Silver models
SAFETY-RELATED COMPONENT WARNING!!
COMPONENTS IDENTIFIED BY MARK (\ ON THE
SCHEMATIC DIAGRAM AND IN THE PARTS LIST ARE
CRITICAL FOR RISK OF FIRE AND ELECTRIC SHOCK.
REPLACE THESE COMPONENTS WITH ONKYO PARTS
WHOSE PART NUMBERS APPEAR AS SHOWN IN THIS
MANUAL. |
MAKE LEAKAGE-CURRENT OR RESISTANCE MEA-
SUREMENTS TO DERMINE THAT EXPOSED PARTS
ARE ACCEPTABLY INSULATED FROM THE SUPPLY
CIRCUIT BEFORE RETURNING THE APPLIANCE TO
THE CUSTOMER, _ |
ONKYO
AUDIO
COMPONENTS
SPECIFICATIONS |
Signal readout system:
Reading rotation:
Optical non-contact
_ About 500~200 r.p.m.
(constant linear velocity)
Linear velocity: 1.2~1.4m/s |
Error correction system: Cross interleave readsolomon code
Decoded bits: 16 bits linear ; |
Sampling frequency: 352.8kHz (8 times oversampling)
Number of channels: 2 (stereo) | ae
Frequency response: 5Hz~20kHz
Total harmonic distortion: 0.004% (at 1kHz)_
Dynamic range: 96dB . |
Signal to noise ratio: 100dB :
Channel separation: = 90dB (at 1kHz)
Wow and Flutter: Below threshold of measurability ;
Power comsumption: 16 watts | eee
Output level: 2voltsr.ms.
Dimensions (W x Hx D): 435x119x312mm
17-1/8°x4-11/16"x12-1/4”
Weight
:
4.7kg,
10.4lbs.
Specifications are subject to change without notice. _

DX-6630)
DX-6630
| | 2. Warning lable |
TABLE OF CONTENTS This label is located on the arm of mechanism.
SPSCIHCAIONS 1) ace tin me aa eel add ae eae ]
Portection on eyes from laser beam during servicing... . . z
Laser warning labels... 2.0... 2 2 ee ee ee eee 2
Caution on replacement of pickup .............-.. 4
Exploded view-parts list... 0.02... ee ee eee 4
Exploded View acs oh ooh goes Se eee eae eas 5
Mechanism-exploded view.................--06- 6
PAROS iG a atau Oc tak Oiute eoes ee Whee ate 3a 7
Disassembling i os Seiiksase SRecbeeh hateas deauare : DANGER = iNvisiBLe fase RADIATION
Adjustment procedures........... ts sata sc taney Assis Bk
Trouble shooting guide... ...............22005 15 AUT 10 i. DIRECT EXPOSURE TO BEAM
IC block diagram and description................ 17 HW. —HAZARDOUS LASER AND
se
PGSCHIDUONS
4-5.
eat
ee
en
edie
es
a5
ANDINTEFLOCK
DEFEATED
ee
chematic diagram. ...... ity hese ens eens Bates TTENTION
—RAYONNEMENT ate
Waveform of each section... ..........2.00000- 29 ET ELECTROMAGNETIQUE DANGEREUX SI
Pc board view & Parts list... 2... eee ee ee eee 31 OUVERT AVEC L’ECLENCHEMENT OF SECURITE
Block diagram... 0.00. ee eee eee 35 ANNULE. $N29360911
PACKING VIEW ica Oct ow Shere eee td ed ae wee 36
ADVARSEL: USYNLIG LASERSTRALING
VED ABNING, NAR SIKKERHEDSAF-
BRYDER ER UDE AF FUNKTION.
UNDGA UDS/ETTELSE FOR STRALING.
Photo 1
Fig. 4
PROTECTION OF EYES FROM LASER BEAM DURING SERVICING
This set employs a laser. Therefore, be sure to follow Laser Diode Properties
carefully the instructions below when servicing. © Material: GaAS/GaAlAs ADVARSEL
ic pNINGH @ Wavelength: 780nm
nt
@
Emission
Duration:
continuous
;
eee
fia
Denne merkning er anbragt pa apparatets h@jre side og indikerer
WwW
: ;
V
J
h
.
.
*
;
e
elder ae pee Ret AE RODE THE TASES sa) held dae max: Oy at apparatet arbejder med laserstraler af klasse 1, hvilket betyder
E TOO CLOSELY. IN CASE IT IS *This output is the value measured at a distance “CLASS 1 LASER td dpe | 3 : ‘
NECESSARY TO CONFIRM LASER BEAM EMMISION, about 1.8mm from the objective lens surface PRODUCT” at der arwendes laserstrater af svageste klasse, og at man ikke p&
BE SURE TO OBSERVE FROM A DISTANCE OF MORE on the Optical Pick-up Block. | | apparatets yderside kan blive udsat for utilladelig kraftig straling.
THAN 30cm FROM THE SURFACE OF THE OBJECTIVE
LENS ON THE OPTICAL PICK-UP BLOCK.
APPARATET
BOR
KUN
ABNES
AF
FAGFOLK
MED
SARLIGT
KENDSKAB
TIL
APPARATER
MED
LASERSTRALER!
LASER WARNING LABEL
The label shown below are affixed.
|
Indvendigt
i
apparatet
er
anbragt
den
her
gengivne
advarselsmerk-
1.
Class
1
label
(Except
120V
model)
ning,
som
advarer
imod
at
foretage
sadanne
indgreb
i
apparatet,
at
This label is located on the back panel. ; :
Pp
man
kan
komme
til
at
udsztte
sig
for
laserstraling.
AOVARSEL USYNLIG LASERSTRALING
VEO ABNING, NAR SIKKERHEOSAF
BRYOER ER UDE AF FUNKTION
UNDGA UDSATTELSE FOR STRALING
VAROITUS! Laite sisaltaa laserdiodin, joka lahettaa (nakyma-
tonta) silmitle vaarallista lasersateilya.
“CLASS 1 LASER
PRODUCT”
Fig. 3

| DX-6630
CAUTION ON REPLACEMENT OF PICKUP
The laser diode in the optical pickup block is so sensitive
to static electricity, surge current and etc. that the com-
ponents- are liable to be broken down or its reliability
remarkably deteriorated.
PRECAUTIONS
1, Ground for the work-desk.
Place a conductive sheet such as a sheet of copper
(with impedance lower than 10°) on the work-
desk and place the set on the conductive sheet so
that the chassis.
2. Grounding for the test equipment and tools.
Test equipments and toolings should be grounded
in order that their ground level is the same the
ground of the power source.
Care should be taken with the optical pickup.
During repair, carefulley take the following precautions.
(The following precautions are included in the service
parts).
3. Grounding for the human body.
Be sure to put on a wrist-strap for grounding whose
other end is grounded.
Be particularly careful when the workers wear
synthetic fiber clothes, or air is dry.
4, Select a soldering iron that permits no leakage and
have the tip of the iron well-grounded.
5. Do not check the laser diode terminals with the
probe of a circuit tester or oscilloscope.
The optical pickup is sensitive to static electricity, surge currents, and other
high electrical noise. and because there is the possibility of damage to
performance. in the handling of the pickup. the utmost care must be taken,
particularly with regard to static electricity.
|. When checking the laser terminal. avoid making connections using the
probes of a tester or oscilloscope, or an ordinary power supply.
2. When replacing the optical pickup, first short the LD terminals and remove
the connector. Also. when attaching the new optical pickup. after attaching
the connector. unsolder the LD terminals.
EXPLODED VIEW-PARTS LIST
REF.NO. PART NO. DESCRIPTION
1 27100190 Chassis
2 27121238-1 Back panel
4 27300750 ¢\ Bushing, cord (Strainrelief)
5 27190266 KGLS-12R, Holder
6 28140946 Cushion
7 27273112 Joint, power
9 272702144 Spacer (Main circuit pc board)
ll 27190706B Holder, mechanism
12 28140928 t4 25 X25, Cushion
13 27141340 Bracket L
15 830440109 4TTC+10C(BC), Tapping screw
16 834430088 3TTS+8B(BC), Tapping screw
17 833430080 3TTP+8P(BC), Tapping screw
18 831130088 3TTW~+8B, Tapping screw
19 834430108 3TTS+10B(BC), Tapping screw
20 833426060 2.6TTP-6P(BC), Tapping screw
26 27110477 Front bracket ass’y <B>
27110477-1 Front bracket ass’y <S>
ol 28184429 Top cover <B>
28184430 Top cover <S>
ag 834430088 3TTS+8B(BC), Tapping screw
51 1H079121 Front panel ass’y <B>
1H080121 Front panel ass’y <S>
38 27211085-2 Tray panel <B>
272110853-1 Tray panel <S>
71 28191512 Clear plate
12 833430080 3TTP+8P(BC), Tapping screw
74 27270255 Spacer
76 27175153 Leg
Optical pickup
LD terminals
Fig. 6
NOTE: <B>: Only Black Models
<S>: Only Silver Models
77 834430088 3TTS+8B(BC), Tapping screw
81 801364 Special screw
82 801414 Special screw
83 27175011C Leg (Cushion)
85 29360911 Label, caution, laser
87 29360687 Label CLASS 1
88 28175158A Insulator plate
P921 253148 or A AS-CEE 250V 2.5A,
253130 Power supply cord
T901 2300385B ‘\NPT-1015G, Power transformer
U1 1H073542-1A NAAR~-3542-1A, Main circuit pc
board ass’y
UZ 1H073543-1 NADIS-3543-1, Display circuit pc
board ass’y
U3 1H073544-1 NAAF-3544-1, Headphone amplifier
pe board ass’y
U4 1H073545-1 NAPS-3545-1, Power supply pc
board ass’y
U5 1H073546-1 NAETC-3546-1, Syncro terminal
pc board ass’y
L901 230907 TR-16-8-16, Core
(2nd side of power transformer)

EXPLODED VIEW
NOTE: THE COMPONENTS IDENTIFIED BY MARK AA
ARE CRITICAL FOR RISK OF FIRE AND
DX-6630
|
Fig. 7
ELECTRIC SHOCK. REPLACE ONLY WITH
PART NUMBER SPECIFIED.

f DX-6630
MECHANISM-EXPLODED VIEW
PARTS LIST
DX-6630
REF.NO. PART NO. DESCRIPTION REF.NO. PART NO. DESCRIPTION
1 27100188A Mechanism chassis 22 28140941 Cushion
2 27301201 Turntable 23 28140947 Cushion
3 24502243 Spindle motor 25 27300942C Cam gear
4 28140948 Tube 26 27300943 Pulley gear
5 82142003 2P+3F(BC), Pan head screw a7 27300944A Gear
6 24110001 KSS-152A, Optical pickup 28 1H025901 Tray motor ass’y
7 27260222 Shaft © 30 27301079 Belt
8 27301191 Rack A 31 82143004 3P+4FN(BC), Pan head screw
10 1H073902 Slide motor ass’y _ 32 27301107 Cushion, rubber
ll 27141230 Bracket, holder 34 25065321 NMS-1113, Microswitch (S002/S003)
12 834430068 3TTS+6B(BC), Tapping screw 35 25065322 NMS-1214, Microswitch (S001)
13 831126060 2.6TTW+6P, Tapping screw 36 2000733B NSAS-6P689, Socket ass’y, motors
14 831430100 3TTW+10P(BC), Tapping screw 37 2000734B NSAS-6P690, Socket ass’y,
15 833420068 2TTP+6P(BC), Tapping screw . microswitches
16 833426060 2.6T TP+6P(BC), Tapping screw (38 2000952 NSAS-8P904, Socket ass’y, white
18 27301190 Arm 39 2000951 NSAS-8P903, Socket ass’y, red
19 27300848A Cap CH 4] 27301192A Rack B
20 27180341A Spring 42 27180426 Spring
21 27301202A Disc tray ass’y 43 27301189 © Cap, arm
44 27300849C Holder, cap
DISASSEMBLING PROCEDURES
Method for removing the tray
Lug for lock
Fig. 10
3. Insert a small flat-bladed screw driver into the hole
section of the right side of the back of the tray, and
push the lug used for locking the tray to bring the tray
i Fa | to the front.
I. Set the position so that the cam gear and gear are
disengaged. CAUTION: When inserting the tray, the cam gear and
2. Pull the tray to the front. gear parts are not in the meashing position.
Method for removing disc motor
. Remove the tray. Cut
. Remove the holder, then remove the arm.
. Remove the 3 screws that fasten the mechanism chassis
to the main chassis.
. Cut the turntable platter with a nipper.
. Remove the soldering of the disc motor, and remove
the 2 fastening screws.
6. When inserting the turntable platter onto the motor
shaft, hold the platter at a right angle to the motor
shaft and push it onto the shaft until it touches the
f bottom.
Wh
an te
LUBLICATION
A :FLOIL G902S
PART NO. 260447
Cut
NOTE: Height of turntable platter.
See page 14.

Focus ; Lon | Focus drive 1
L * eel Focus offset
DX-6630
CIRCUIT DESCRIPTIONS
+5V
Focus error (FE)
signal (A+C)—(B+D) Pane ci28
tek R133
| +5 VA P105 a : ie dig Risa |
Petts
4
101
1RIG2
3
=
:
j demas eqn eanann Outs Crh epeiphe nea GS cumin dene ae ene eee { H
BS orgs U ae On ao7 A |
| (focus zero * On
RIZ3 cross) ~—s [Phrase \_RI32
i 8) correction |b >—(5)“{2) DD (8)
} !
RI \
72 cla ;
| f ees 7a
i
I
ee mere meee seats ey champs None Si
“fs
RHO RIG
Optical pick-up
‘and offset adjustment
1. Focus servo circuit
From the optical pickup objective lens, the emitted laser
beam is focused on the disc reflecting surface, an this
circuit controls the movement of the lens up and down.
1-1. Error detecting circuit
The error is detected by means of the astigmatic aberration
method and obtains its focus error signal from the optical
pickup output signal (A+C)—(B+D). |
The individual signals (A+B) and (C+D) input to pins 7 and
8 of Q102 are subtracted by means of the IC internal op
amp, and from pin 19, the F.E. signal is output. Also, in
order to eliminate the focus error, offset adjustment is
carried out by the semi-fixed resistor R110 of pin 18 of
Q102.
1-2. Phase correction and driver circuit
By means of the semi-fixed resistor R122, the gain adjusted
F.E. signal passes by way of the phase correction circuit
from pin 48 of Q104, and from pin 5S of Q104 to the driver
Q107, and is feedback to the coil used for driving the
optical pickup KSS-152A objective lens. In addition, there
are the FS4 servo ON/OFF switch and FS3_ phase
characteristic selector switch.
1-3, Focus zero cross circuit and focus search circuit
In order to have mandatory drive of the objective lens in
the capture range of only 10um at the focus point it is
necessary to turn off the above mentioned FS4 and close
the servo loop. The timing diagram for that operation is
shown in Fig.13.
The triangular wave generated by means of the focus search
circuit internal to Q104 shifts the objective lens up/down
direction, and at the correct focus point, the fall of F.E.
signal is detected by the focus zero cross (FZC) circuit to
close the servo loop. At this time, it is necessary that the
focus OK (FOK) signal be in the high level. In Fig.13, the
dotted line is the waveform of the focus capture failure.
Focus gain
———— adjust.
RUS Focus servo ON/OFF
adjustment
Preamp., error detector, Gain adjustment
Phase
switching
Focus
search
switching
Facus search
circuit and driver
Phase correction and
zero cross detector
Fig. 12 Focus servo circuit
Servo ON
“
5
about 3.5V
Focus.drive output
2 Capture |
start
F.E.
\
“
5V_ |
x
FOK | ne eee
5V
FZC | |
SENSE .
terminal ov
Fig. 13 Capture operation of focus
R GND
P105 #1
Test
point
GND
FO
1Vidiv. (Lower) 7.
O.5V/div. (Upper)
2ms/div.
Focus signal
Photo 2
Tracking coil EB | |
i
"Smet
narnhomel
KSS-I52A) Tracking
drive output RI08——L_
RIO9 = Tracking offset
adjustment
Preamp, error detector Gain
Sea ee
é and offset adjustment
Optical pick-up
2. Tracking servo circuit
On the disc at.a pitch of 1.6um, the laser beam accurately
traces the center of the pits cut into the disc, and this is the
control circuit that shifts the objective lens in the radial
direction.
2-1. Error detection circuit
The F-E is obtained from the tracking error (T.E.) signal by
~~ means of a 3 beam method. The F.E. signal input to pins 10
and 11 of Q102 is subtracted internally, and is output as
the T.E. signal from pin 20. R108 is the semi-fixed resistor
control for tracking offset.
2-2. Phase correction and driver circuit
The T.E. signal adjusted for gain by means of the semi-fixed
resistor R125 passes through the phase correction circuit
from pin 45 of Q104, and from pin 11 by way of driver
Q107 objective lens. TM1 and TM7 are used as the tracking
servo ON/OFF switches, and TG! and TG2 respectively are
used as the phase selector and gain selector switches.
wer GND
P105
#3
0.5V/div. 0.5ms/div.
Tracking signal
Photo 3
adjustment
135
Tracking error (T.E) signal R62
Servo
ON/OFF
Tz¢
(tracking :
zero cross) (9) a
Track kick circuit and driver
Phase correction
and tracking zero cross detector
Fig. 14 Tracking servo circuit
2-3. Tracking zero cross and track kick circuit
At the time the head comes out and when there is manual
fast forward, in the event that is it necessary to skip over
the track being traced, the T.E. signal receives a kick pulse,
and by mens of this, shifting of the objective lens can be
achieved.
TM3 and TM4 respectively are the switches for providing
the forward and reverse direction kick pulses. Also, the
tracking zero cross (TZC) circuit counts the number of —
tracks skipped over and produces the signal in order to
determine the timing of the servo ON/OFF.
The ON/OFF command for these switches is output from
the microcomputer.
0.2 us/div. 0.5mV/div.
Signal HF (RF)
Play the track 2 of YEDS-18.
Photo 4

Ci04 PIOS
7
! RIO6 RIOS
Boe
S eneeinananetiicene:eadiessene Teese tiencecdin a
goes high, the servo and gain are controlled, and the circuit
prevents a sound outburst.
4. APC circuit | |
By means of feedback from the monitor, this circuit
controls the light output due to a bad condition resulting
from the temperature characteristic of the laser diode.
For the pin 29 LDON (laser diode ON) signal, when the
APC ON/OFF control signal is LOW, the laser is emitted.
5. CLV servo circuit
In the compact disc there is a CLV system (constant linear
velocity), and at the replay position, because the disc rotary
speed varies, the clock is taken out of the HF signal, and
HF signal (eye pattern)=
A+B+C+D
HF
—10—
the PLL circuit and its clock must be synchronized to
Asymmetry signal control the spindle motor.
component of the tracking driver output is amplified and
fed to the motor, but when the head is extended, switches
TMS and TM6 internal to Q104 control the ON/OFF.
Fig. 17 PLL circuit
DX-6630 4
5-2. Spindle motor control circuit
The output of the phase comparator (MDP) and frequency
comparator (MDS) from pins 3 and 4 of Q109 is fed to pins
34 and 36 of Q104. Also, the spindle motor ON/OFF
2
A+Cc @ NO va > reyKey=' 5-1. PLL circuit
| x i As shown in Fig. 6, for the phase comparator, in Q109 the signal (MON) from pin 2 of Q109, and the phase selector
qe eS RI Ril2 lt i i-fi ignal (FSW) f in 1 tput and fed to pin 36 of
ee y <i G6) (6) LPF and VCO are each built into Q104. The semi-fixed signa rom pin 1, are output an O pin 50 0
54D ae | Va Coote, | A resistor R147 is the control for adjusting the 8.6436 MHz QI104. After these signals are processed in Q104, they are
C103 | CHO Cll! R free run frequency (WFCK = 7.35 KHz). passed from pin 39 through the driver Q108, and are
| > 2) mel Or) ie Oma supplied to the spindle motor.
| Scales Pee EFM signal Ri27
| Re Mir
Qt:
AA
a
>
sional
ciieant
22)
:
MIR
Q109
Q104
isa
aoe
3. HF (RF) amplifier r | f . | a = Satddlaaigror
This
circuit
feeds
the
A+B+C+D
to
the
amplifying
and
form
|
rt
eens)
Or
siene!
FSW
&
ON/OFF
Ri29
processing circuit together with the data HF (RF) signals! | CIOs MON nal | he SP
due
to
the
pits
cut into
the
disc,
checks
the
servo
condition,
I
ni
|
Sams
BS
69
iad
°
S
and transmits that data to the microcomputer. Re ee MDP CPF R128 oe
I
see
,
et
|
Focus
OK
MDS
(4)
|
a
3-1.
HF
amplifier,
waveform
shaping
circuit
i
circuit
e8)
Pocus
OK
|
=
The At+C and BtD signals input to pins 7 and 8 of cee IRII3 ee omens: i; |) Sere NSS pee a ee re ee a Q108 x FAQS
-added by the op amp, and the HF signal (eye pattern)| | ee
AtB+C+D is output from pin 2. The HF signal then passes | z ciao oe
through C103 and R118 entering at pinl, is shaped by Ci39 . : srcui
; Lm | Fig. 18 dle motor control circuit
means of the comparator, and becomes the EFM signal rp bie @ 1) DFCT = een nary eres
which is output from pin 27. l | a ae es ‘| Fast forward
In the comparator threshold value, the EFM signal low thr 4 Defect signal | Pe
region component ASY (asymmetry) is input from pin ee (5)}-(6)-—- RI36 : > TMG
and control is achieved by this means. Cio? Fig. 15 HF amplifier circuit cizj ——~ Fast rewind a | RIGO
RI4I
|
3-2. MIR circuit, FOK circuit, and DFCT circuit’ ~~~ oe gio7 VA, Ny 8 :
After the HF signal is processed the detection, shaping, etc, Driver —_ Ci) FA LEMS A SLD
respectively the MIR, FOK, and DFCT signals are output LPF is Slide motor
from
pins
22,
28,
and
21,
7
RI37
EO)
e
6
t1@
UW
R135 oS © ot 8 A ae 7 ad
3-2-1. MIR (mirror) signal ue | ciS2 |
When the head is extended, at the time the signal becomes ry A | R138 af | Saari P104
high at the disc track and between tracks, the number of Ww Ls) ie, Cea NOE L
tracks
is
counted,
and
this
is
used
for
determining
the
YZ
M.0
Q104
|
timing for the ON/OFF of the servo, —3 > hs a : SGiOEL” Driver
. -5 | | i ee i Fig. 19 Slide motor circuit
3-2-2. FOK (focus OK) signal Monitor output P102 | xss-isza
This signal goes high at the time the focus servo is required. pail 6 Side metarcivcuit
Refer to 1-3} 4
SSerone? Fig. 16 APC circuit This circuit controls the slide motor which is used for
3-2-3. DFCT (defect) signal moving the optical pickup from inside the disc to the
If there is a defect (scratch, dirt, etc.) in the disc, this signal CUTE ee Dotnet Play eee iy res ow Seen Q104 #32
PLCK
1V/div. (Upper) 2V/div. (Lower)
0.1 us/div.
Photo 5
5 ee

| DX-6630
ADJUSTMENT PROCEDURES
Instruments required
Dual
trace
oscilloscope,
Frequency
counter,
AF
oscillator,
Test
disc
(SONY
YEDS-18),
AC
voltmeter,
Jitter
meter,
Sockets
P106
&
P107
(Part
No.
25050089)
P105
(Part
No.
25050138)
1. VCO frequency adjustment
Connect the frequency counter to terminal P107.
Turn the power switch to ON.(No load the disc.)
Adjust R147 until the frequency counter reading becomes
4322 +SkHz. |
After adjustment, disconnect the frequency counter.
2. Focus offset adjustment
Load the test disc YEDS-18 on the tray and play the track 2.
Connect the oscilloscope or jitter meter to terminal P106.
(Oscilloscope) ;
Adjust R110 until a clear trace of waveform pattern as
shown photo 1 appear on the oscilloscope.
When the amount of jitter is broad, set R110 to mechanical
center.
(Jitter meter)
Adjust R110 until the jitter meter reading becomes
minimum.(Less than 10ns.)
After adjustment, disconnect the oscilloscope or jittter
meter.
Frequency
P107 counter
Use the high impedance probe more than 10 MQ.
HF + , Oscilloscope range
Vertical : 0.2V/div.
- Holizontal :0.5 ps/div.
‘Oscilloscope
Photo 6
3. Tracking offset adjustment
Play the track 2 of test disc.
Turn R125 to minimum position.(Counter clockwise)
Connect the oscilloscope between pin 3 (TR) of P105 and
pin 2 (GND) of P106.
Adjust R108 until the center of tracking error signal on
the oscilloscope becomes GND level.
Turn R125 to the mechanical center.
After adjustment, disconnect the oscilloscope.
Oscilloscope
Vertical : 50mV/div.
Holizontal : 0.2 ps/div.
DC, Ground: Center
—12—

4. Focus gain adjustment
Set the output of AF oscillator to 800Hz, 1~1.5Vp-p.
Play the track 2 of test disc.
Connect the oscilloscope and the AF oscillator as shown
_ below.
owe dew
ee | - Photo 8
Adjust R122 until 800Hz components of channels 1 and
2 on oscilloscope become same level.
After adjustment, disconnect the AF oscillator and the
oscilloscope.
5. Tracking gain adjustment
Set the output of AF oscillator to 1.2kHz, 1~1.5Vp-p.
Play the track 2 of test disc.
Connect the oscilloscope and the AF oscillator as shown
below.
[a
A=B
Photo 9
Adjust R125 until 1.2kHz components of channels 1 and
2 on oscilloscope become same level.
After adjustment, disconnect the AF oscillator and the
oscilloscope. |
6. MSB adjustment
Play the track 2 of test disc.
Read the output signal and regard it as 0 dB. Then, play the
track 17. a
Adjust R403 (R404) so that the output level becomes
—60dB.
NOTE: (__): R channel
. [p
---L.. P1005
- Oscilloscope
AF
oscillator
GND CH 1 CH 2
Vertical + 0.5V/div..
Holizontal: 1 ms/div.
AF . 258 “Oscilloscope Site Bieseee Ba laatiee ae
oscillator
GND
CH1 CH2
Vertical : 0.5V/div.
_ Holizontal: 0.5 ms/div.
—13—
MECHANISM ADJUSTMENT
Height of turntable platter.
Turntable platter
10.5 + 0.1mm
Chassis
Fig. 21
Tray motor
8.2 + 0.1mm
Fig. 23
—~14—
vco
PIOS
RI25 Ee
1
TRACKING
GAIN
RI22 RIO
FOCUS FOCUS
GAIN OFFSET
Fig. 20 ADJUSTMENT POINT
Slide motor
22.6~22.8mm
Fig. 22
1B) Ge loxe 1 @)

TROUBLESHOOTING
GUIDE
Symptom:
Defective
reading
(No
RF
signal
emitted)
Load
the
disc
on
the
tray,
press
OPEN/CLOSE
key
and
close
the
tray.
But,
the
total
number
of
tunes
are
not
indicated
on
the
fluorescent
indicator
tube.
Does
tray
open
for
some
time?
No
Does
pickup
returned
to
innermost?
Is
the
$003
start
switch
ON?
Yes
Continuously
ON
Method
for
checking
S003
Zonnect
oscilloscope
to
pin
3
of
P103,
does
it
momentarily
go
to
OV.
1.
Remove
the
top
cover.
2.
Does
the
disc
turn
clockwise?
.......
Yes......
Next
page
No
....
Remove
the
bracket
holder
and
arm
ass’y.
Check
the
following
when
turning
on
power
without
the
disc.
Chucking
mechanism
Chucking limit switch (IN switch S002)
+-++ Tray does not close.
....
Confirm
that
the
slide
motor
runs
smoothly
with
the
tester
(ohm
range)
or
1V
DC
applied
to
both
ends
of
the
motor.
....
Bring
the
pickup
to
the
outermost
circumference.
After
power
source
is
applied
to
SLD
terminal,
is
the
voltage
-2V
to
4V?
Yes
...
Slide
motor
defective
No
...
Q104
pin
14
(check
at
leads
of
R139):
when
low,
Q104
is
defective,
if
pulse
emitted
at
CLK
(J158),
XLT
(J157),
DATA
(J160)
and
when
not
emitted
at
0104,
Q107
is
defective.
GND
| |
GND
G
Check
rack
PU
movement
Slide
motor
circuit
S003:
Start
switch
Q751-»Q104—0107
Not
ON
Yes
$003
ov
Fig.
24
CLK(J158)
XTL(J157)
DATA(J160)
L
_5y
STOP:
5V
STOP:
5V
STOP:
0V
OFF
ON
OFF
Does
No
Optical
pickup
(Q101
ON,
pickup
ON
with
collector
at
2V
laser
APC
circuit
(Pin
32
of
Q751
LSR
OV,
Q101
base
low
light?
check).
P102
socket
insertion
defective.
Q109
oe
When
the
START
switch
is
ON
continuously,
the
laser
is
lit
80
Yes
continuously,
and
the
focusing
coil
does
not
go
up
and
down
24
1
sides.
Check
the
gear
meching.
Does
the
No
Does
a
search
voltage
of
Yes
sees
object
lens
—2V
~3V
output
at
the
Optical
pickup
defective
J156
XRST
move
to
up
and
focus
drive
output
P102
socket
insertion
J157
XLT
down
sides?
test
point
FO?
defective
3158
CLK
J159
S.
SW
|
J160
DATA
Yes
J161
SENSE
Q104,7
focus
search
circuit
Fig.25
test
point
No
Does
the
disc
start
to
turn
clockwise? optical pickup -® Play the track 2 of test disc. (YEDS-18)
ves
High
MON
Does
pin
2
of
Q109
turn
at
Peis
an
7
high
level?
Low
Hoes
the
test
Low
point
GFS§
turn
at
the
high
level?
High
Q107
or
Q109
trouble
Asy
PLL
circuit
trouble
of
Q102
turn
at
Spindle motor control
| circuit trouble
Does
pin
26
of
of
Q102
turn
at
NOTE:
There
is
the
possibility
that
the
pickup
lens
is
so
dirty
that
it
is
impossible
to
read.
Clean
with
a
lens
cleaner.
FOK
Low
Focus
servo
circuit
or
adjustment
miss
Does
pin
26
of
Je
@
Use
the
high
impedance
probe.
(10:1)
lelote
RISK
ste
#008
FOK
:
Be
RF
signal
Tracking
signal
en
ah
Low
P106
pin
2
(HF)
P105
pin
4
(HF)
at
high
level:
V:
50mV/div
V:
20mV/div
:
H:
0.5S/div
Photo
10
H:
0.5mS/div
High
level
more
than
1
sec.
Is
the
No
tracking
OK?
os
Tracking servo circuit
trouble
or
adjustment
miss
Contirm
the
HF
signal
(eye
pattern)
or
tracking
singal.
Yes
*
2.5V
HF
waveform
sharp
high tevel? circuit trouble
=
2.5V
Higher
speed
or
lower
speed
Rotation
speed
of
disc
OK :