Onkyo DX 7500 Service Manual

Page 1

DX-7500

SERIAL NO 3308

ONKYO® SERVICE MANUAL

COMPACT DISC PLAYER

MODEL DX-7500
BIaEk model
BUDN, BUD 120V AC, 60 Hz
BUG 220V AC, SOHZ
BW, BWX 120/220V AC, 50/60 Hz
BUQA, BUQB 240V AC, 50 Hz
SAFETY-RELATED COMPONENT WARNING SPECIFICAT|ONS
COMPONENTS IDENTIFIED BY MARK A ON THE Signal readout system: Optical non-contact
QCHEMATIC DIAGRAM AND IN THE PARTS LIST ARE Reading rotation: About 500~200 Rpm.
CRITICAL FOR RISK OF FIRE AND ELECTRIC SHOCKI (constant linear velocity)
REPLACE THESE COMPONENTS WITH ONKYO PARTS Linear velocity: 1.2~1.4m/s
WHOSE PART NUMBERS APPEAR AS SHOW IN THIS Error correction system: Cross interleave readsolomon
MANUAL. code
Decoded bits: 18 bits linear
MAKE LEAKAGE-CURRENT OR RESISTANCE MEA- Sampling frequency: 352.8kI-Iz (eight-times
SUREMENTS TO DETERMINE THAT EXPOSED PARTS oversampling)
ARE ACCEPTABLY INSULATED FROM THE SUPPLY Number of channels: 2 (stereo)
CIRCUIT BEFORE RETURNING THE APPLIANCE TO Frequency response: 5Hz~20kHz
THE CUSTOMER Total harmonic distortion: 0.0015% (at lkHz)
Dynamic range: 103dB
Signal to noise ratio: llOdB
Channel separation: 103dB (at lkHz)
Wow and Flutter: Below threshold of
measurability
Power consumption: 23 watts
Output level: 2 volts r.rn.s.

ONKYO
AIIIIIII IIIIMPIIIIIIIISJ

Dimensions (WXHXD): 435x131><365 mm
17-1/8><5-1/8"><14-7/16"
Weight: 8.8kg, 19.4 lbs.

Specifications are subject to change without notice.

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DX-7500

TABLE OF CONTENTS

Specifications ...........
Service procedures .
Note on compact disc ........................................
Protection of eyes from laser beam during servicing
Laser warning label ..................
Caution on replacement of pickup
Packing view
Chassis-exploded View
Parts list
Mechanism-exploded view
Parts list ...........................
Disassembling procedures ..
Lubrication ....................
lC block diagram and descriptions
Adjustment procedures ..................
Printed circuit board View from bottom side

Main circuit ......... . 25
Other pc boards , . 29
Printed circuit board-parts list , 27
Block diagram ...................... . 31

SERVICE PROCEDURES

1. How to Release the Transport Lock

Tepfijteétahetoptical assembly including the laser pickup
vaihfatlcn'related damage during shipping. this unit
til equipped plit'h utransport lock lever located on the base.

n

(a Cg?

head screwdriver

Lock lever Hole

0 Use a screwdriver to turn the lock lever (about 90°) in
the round hole in the direction of arrow ( 0 ).

0 Before transporting the unit again, stand it with its left
side facing down, and turn on the power. Wait 2-3
seconds and then turn the lock lever in the opposite
direction of the arrow.

Fig. 1

2. Safety-check out

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

more.

Form of soldering irons tip:

(2) Mngnifyingglass . . . for checking of finished

works

(3) Tweezers ........ for handling of IC and
forming of leads

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

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

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

2. Work Procedures:

(1) Remove the defective 1C
Cut all leads of the defective lC 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 pack
aged [C to be installed.
From every lead on the new lC 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.

lc g ! IC 5: g IC 2/
(Rising) lTwistingl (Incliningl

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 ICs leads are to
be soldered.

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

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 ping
of power supply cable and chassis.

Specifications: more than 10Mohm at 500V.

egg

About 2.5 mm

Fig. 4