Onkyo DX 230 Service Manual

Page 1

DX-23O

SERIAL NO. 3266

ONKYO® SERVICE MANUAL

COMPACT DISC PLAYER
MODEL DX-230

Black model
BUDN, BUD I I 120V AC, 60 Hz
BUG = l 220v AC, 50Hz
BUU l 1 10/120/220/240V AC, 50/60Hz
BUQA 240v AC, so Hz
SAFETYtkELATED COMPONENT WARNING SPECIFICATIONS
COMPONENTS IDENTIFIED BY MARK A ON THE Signal readout system. Optical nonfiomact
SCHEMATIC DIAGRAM AND IN THE PARTS LIST ARE Reading rotation: About 500~200 12pm.
CRITICAL FOR RISK OF FIRE AND ELECTRIC SHOCK. (constant linear velocity)
REPLACE THESE COMPONENTS WITH ONKYO PARTS Linear velocity: 1.2~l .4m/s
WHOSE PARTS NUMBERS APPEAR AS SHOWN IN THIS Error correction system: Cross interleave readsolomon code'
MANUAL. Decoded bits: 16 bits linear
Sampling frequency: 88.2kHz (two-times oversampling)
MAKE LEAKAGE-CURRENT OR RESISTANCE MEAA Number ofchannels: 2 (Stereo)
SUREMENTS TO DETERMINE THAT EXPOSED PARTS Frequency response: SH2~20kHz
ARE ACCEPTABLY INSULATED FROM THE SUPPLY Total harmonic distortion; 0.03% (at lkHz)
CIRCUIT BEFORE RETURNING THE APPLIANCE TO Dynamic range: 93dB
THE CUSTOMER. Signal to noise ratio: 96dB
Channel separation: 87dB (at IkHZ)
Wow and Flutter: Below threshold of measurability
Power comsumption: 13 watts
Output level: 2 volts r.m.s.

Dimensions (W x H x D): 435 x 88 x 357mm
17-1/8" x 3-7/16" x 14-1/16"
Weight: 4.8kg, 10.6 lbs.

Specifications are subject to change without notice.

ONKYO
AIIIIIII L'IIMPIIIIIIIIS

Page 2

DX-230

TABLE OF CONTENTS

Specifications ............................ 1
Service procedures ......................... 2
Note on compact disc ....................... 3
Protection of eyes from laser beam .............. 4
Laser warning label ......................... 4
Caution on replacement of pick-up .............. 6
Packing view ............................. 7
Exploded view ............................ 8
Parts list ................................ 9
Mechanism exploded view ................... 10
Parts list ............................... 1 1
Disassembling procedures .................... 12
Circuit descriptions ....................... 14
Trouble shooting guide ..................... 19
IC descriptions ........................... 21
Adjustment procedures ..................... 25
Pc board view from bottom side ............... 26
Schematic diagram ----------------------- 31
Pc board-parts list ......................... 33
Waveform of each seetion .................... 35
Block diagram ........................... 37

SERVICE PROCEDURES

1. Removing the Locking Plate

Locking plate is located on the bottom panel of this unit.
Before using this unit for the first time, the plate must be
removed. If power is switched on while this part is still in
place, the unit will not operate properly

1. Locking plate
2. Tapping screw

Fig.1

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 chassis.

Specifications: more than 10Mohm at 500V.

3. Proceduresfor replacement of flat packaged [Cs
1. Tools to be used:
(1) Soldering iron . . .. Grounded soldering iron or
soldering iron with leak re-
sistance of 10 Mohms or

more.

Form of soldering irons tip:

(2) Magnifying glass . .. for checking of finished
works

(3) TweeLers ........ for handling of IC and
forming ofleads

(4) Grounding ring . . . . Countermeasure for electro-
static breakdown

(5) Nipper ......... for removing defective [C

(6) Small brush ...... for application of flux

2. Work Procedures:

(1) Remove the defective lC
Cut all leads of the defective IC one by one using
a nipper and remove the 1C.

(2) Clean the pattern surface of the PC board.
Get rid of the remaining leads and solder.

(3) Check and from the leads of the new flat packv
aged [C to be installed.
From every lead on the new IC using a pair of
tweezers, so that all of them are aligned neatly
without being risen, twisted or inclined toward
one side. Especially the rising portion of every
lead must be formed with greatest care.

16 IC lc /
gé 3; \E
(Rising) (Twisting) llnclining)

Fig. 3

(4) Apply flux to the PC board.

Apply flux to the pattern surface of the PC board
which has been cleaned, as shown in the illustration.
The area to be applied with flux is the portion of
about 2.5mm in width where the [CS leads are to
be soldered.

Be careful to apply minimum amount of flux
required so as not to smear it on unwanted areas

eases

About 2.5 mm

Fig. 4

Page 15

2. Tracking servo

This control circuit moves the objective lens radially
to keep the laser beam precisely centered in the tracks
on the disc surface (which are only l.6,um wide).

, 5 Tracking Tracking
Tracking R2 onset 93m
error signal adjustmenl adjuflmm
r. E c 204 P RZODI
:. - ~-vw--
Optical pickup 3 1 "5" *les m': K use R262
MLP-E (S) (3) .w KF+ m "
R275 1-1 czar-3
;
227 -
,-~-1 C226 1-
E ' R276 | }-t c249 D
'5 R207 R274 R27| I we"
F R277 + IT m u. '6 azsa R267
[9 |
l
223 R270
R278 L - J
I :25

Tracking Call balance
7m FIOZ actustment

Tracking drive output

|_ _____
l
|
l
__s _J
l
|
I
L_Q
R297
rnor ---m--
R279 R258
rsor .__ ram;
4
c245

Fig-3

2-1. Tracking Error Sensor
This unit uses a threebeam laser pickup, The error
signal is obtained from the difference between the E
and F output front both sides of a four-section
photodiode housed in the pickup.

T.E. (tracking error) = F e E
The E and F signals are input into pins 18 and 19 of
QZOI, the difference is obtained by an internal opamp,
and the TE. signal is output from pin 17.

2-2. Phase Correctors - Drivers

The tracking error signal is relayed from 0201 pin 17
to pins 16, 15, 7 and 6 in succession, After passing
through drivers Q2l7 and Q218 it drives the tracking
coil of the pickup. C226, C249, C225 and C224 are
capacitors which perform phase corrections. Balance,
offset and gain are regulated by semi-fixed resistors
R279, R273 and R269 respectively.

The switches incorporated in pins 12 and 13 of 0201
turn the servo on and off and switch the high frequency
range loop gain on and off, thereby helping to stabilize
transient operation during access times. The timing of

these switches is determined by the input into pins 9
7 11 of 0201, The commands are as follows:
TROF (tracking OFF) FEOF (feed OFF)
TRGL (tracking gain low) TRHD (tracking high
down)
Signals are output from 0202 in response to commands
from microprocessor 0204.

2-3. TER circuit

The TER signal is one of the sensors that determines
the switch timing mentioned above. It is produced by
running the tracking error signal output from pin 15
through a comparator at the ground level and then
output through pin 14.

_15_