Onkyo DX 150 Service Manual

Page 1

DX7150

SERIAL N0. 3203

ONKYO SERVICE MANUAL

COMPACT DISC PLAYER
MODEL DX-150

Black and Silver models

UDN, UD 120v AC, 60Hz
UGV, UG 220v AC, SDHz
UW 120/220v AC, 50/60Hz
SAFETY-RELATED COMPONENT WARNINGII SPECIFICATIONS
COMPONENTS IDENTIFIED BY MARK A 0N Type; Comm Disc player with
THE SCHEMATIC DIAGRAM AND IN THE PARTS opticalpickup
LIST ARE CRITICAL FOR RISK OF FIRE AND Quantum; 16mm
ELECTRIC SHOCK. REPLACE THESE COM. Chafing: 2 (Stem)
PONENTS WITH ONKYO PARTS WHOSE PARTS quuemympme: 10Hz~20kflz m];
NUMBERS APPEAR As SHOWN IN THIS MANUAL. Dynamic Huge; 0m 9m
MAKE LEAKAGE-CURRENT 0R RESISTANCE Total harmonic distortion: 0.005% (1kHz)
MEASUREMENTS To DETERMINE THAT 3:? 3mm: 371" at:
EXPOSED PARTS ARE ACCEPTABLY INA W/ 3:11 _ 3"
SULATED FROM THE SUPPLY CIRCUIT BEFORE 0 1 m- ngfsmbe
RETURNING THE APPLIANCE To THE :13" S' Y" Sumo, 1m 1
2 BmlCO ype
CUSTOMER. Power consumption: 26 watts (D), 29 watts (G/W)
Dimensions: 435 (W) x 92 (H) x 350 (D) mm
Weight: 5.0kg
Accessories: Connection cables

Specifications are subject to change without notice.

ON KYO®
Alllllll BIIMPIINENISL

Page 2

DX-ISO

TABLE OF CONTENTS

Specifications ................................. 1
Precautions ........... . . . 2
Notes on compact disc ............ . . . . 2
Cautions on replacement of pick-up ................. 3
Protection of eyes from laser beam during servicing ..... 4
Laser warning labels ............................. 4
Adjustment procedures .......................... 6
Packing View .................................. 10
Chassis exploded view ........................... 1 1
Parts list ..................................... 11
Mechanism exploded view . . . . . . . l3
Partslist .................... . . . 14
PC board view from bottom side . . . . 15
Parts list .................... . . . 15
Service guide .................................. 21

PRECAUTIONS

l. The Pickup Attachment Screw

There is a pickup shipping screw on the bottom of the
cabinet. Before playing a disc for the first time, this screw
must be turned clockwise using a blade (4) screwdriver or
coin. If the power is turned on with this screw attached, the
unit will not operate properly.

2. Safety-check out (U.S.A. model)

After correcting the original service problem, perform the
following safety check before releasing the set to the
customer:

Connect the insulating-resistance tester between the plug
of power supply cable and shassis.

Specifications: more than lOMohm at 500V.

3. Replacing the fuses
For continued protection against fire hazard, replace only
with same type and same rating fuse.

Only G/W models

Circuit no. Part no. Description
1801 252063 SOOmAAEAWK, Secondary
1802, 5803 252070 lA-EAK, Secondary

NOTE ON COMPACT DISC

0 Holding Compact Discs

Hold Compact Discs by the edges so that you do not touch
the surface of disc. Remember that the side of the disc with
the rainbow reflection is the side containing the audio
information.

Do not attach tape or paper to the label side of the disc
and always be careful not to leave fingerprints on the side
that is played.

I Storing Compact Discs

Store Compact Discs in a location protected from direct
sunlight, high heat and humidity and extremely high
and low temperatures. Discs should never be left in the
trunk or interior of an automobile in the sun since the
temperature can become very high in such a closed environ-
ment.

Always store Compact Discs in the holders in which they
were sold. Never leave a disc in the players disc holder for
a long period of time.

Not this way

0 Cleaning Compact Discs

Before playing a disc wipe off the playing surface with a
soft cloth to remove dust and other soil. Wipe the surface
in straight lines from the center of the disc outward, not
in a circular motion as you would with a phonograph
record.

Do not use benzene, chemical cleansers or phonograph
record cleaning solutions to clean Compact Discs. Also
avoid static electricity prevention solutions since they can
damage the surface of Compact Discs.

Problems Caused by Dew

Dew can form inside a Compact player when it is brought
from a cold environment into a warm room, when a room
is rapidly heated and if a player is left in a humid environ-
ment.

This dew can prevent the laser pickup from reading the
data contained in the pits in the disc surface. If the player
does not operate properly because of dew, remove the disc
and leave the players power switch on for about one
hour to remove all moisture.

Page 22

DX-150

7. Tracking Error Circuit

B D Four-part
Outside A C photodetector
On track
(Disc)
. Shadow on the four-part photodetector
InSIde due to pit reflection
g .4
T51 85¢ U
(A+C) s: _-_._._-__-_-_._-_._ 0
< o
T82 EE W
(3+0) ggt -----'*-"- 0
< 5 l;
TS1-TSZ Es
T81 82% W
(AtCI g5 _._____,___________ 0
E .u
T52 STEM M 0
B+D) E :-
( <( O / \ +
T517192 " ' 9
Center of
- 3 e- =-- ' - = - beamspot
TSI _______ A__ __ ___ _ ,7, A___
(A+C) W \.-7 < 7 V /
T82 ____ _ _ __> ___ V__ __ __ __
tB+D) T 7 V VI \_7
m +
TS'l-TSZ

W 0

\

Integral
wave

Fig, 9 Tracking error generation circuit by push-pull system

The purpose of the tracking error circuit is to generate
an error circuit when the beam spot moves away from the
center of the pits, thereby enabling the beam spot to
correctly track the pits,

The above diagram shows how the push-pull system ope-
rates. (Fig. 9)

As the spot of light deviates from the pit, the amount of
light striking on the photodetector varies and, as a result,
the output of the amplifier also varies. If the track coil is
moved in the direction opposite to the change of amplifier

output by a tracking servo to return the output of the

amplifier to 0, then the spot of light will always be

positioned on the pit.

The advantages of the push-pull system are as follows:

0 There is no offset in the tracking error signal

0 The tracking error signal is free from focus balance.

0 The variation of offset in the tracking error signal caused
by temperature changes is small.

0 The circuit is simple and a general-purpose operational
amplifier can be used