Sharp md x 8 h service manual

Page 1

MD-X8H

SHARP SERVICE MANUAL

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O SRS technology Licensed from SRS Labs. SRS tech-
nology holds the following patents:U.S. Patent No.
4,748,669 and US Patent No. 4,841,572.

0 SRS, the SRS Logo (0) and the
SOUND RETRIEVAL SYSTEM are registered trade-
marks ot SRS Labs, Inc. in the United States. . . .

, , , - In the Interests of userrsatety the Set Should be restored to Its original

Us and foreign patents licensed from Delby Laboratones condition and only parts identical to those specified Should be used.

Licensing Corporation.

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DIGITAL AUDIO

/- CONTENTS E

SAFETY PRECAUTION FOR SERVICE MANUAL
IMPOTANT SERVICE MANUAL (FOR UK ONLY).
SPECIFICATIONS .....
NAMES OF PARTS
OPERATION MANUAL.
DISASSEMBLY .................
REMOVING AND REINSTALLING THE MAIN PARTS.
ADJUSTMENT ...................................
NOTES ON SCHEMATIC DIAGRAM
TYPE OF TRANSISTOR AND LED
WIRING DIAGRAM
BLOCK DIAGRAM .....
SCHEMATIC DIAGRAM / WIRING SIDE OF P.W.BOARD ..
VOLTAGE ...................................
WAVEFORMS OF CD CIRCUIT.
WAVEFORMS OF MD CIRCUIT
TROUBLESHOOTING (CD SECTION) .
TROUBLESHOOTING (MD SECTION).
FUNCTION TABLE OF IC ......................
WIRING OF PRIMARILY SUPPLY LEADS (FOR UK ONLY) .
RDS OPERATION ...................................................................
REPLACEMENT PARTS LIST/EXPLODED VIEW/

PACKING OF THE SET (FOR UK ONLY)

-
This document has been published to be used

SHARP CORPORATION for after sales service only.

The contents are subject to change without notice.

Page 2

MD-X8H

SAFETY PRECAUTION FOR SERVICE MANUAL

WARNINGS (CD)
THE AEL (ACCESSIBLE EMISSION LEVEL) OFTHE LASER
POWER OUTPUT IS LESS THAN CLASS 1 BUTTHE LASER
COMPONENT IS CAPABLE OF EMITTING RADIATION
EXCEEDING THE LIMIT FOR CLASS 1. THEREFORE IT IS
IMPORTANTTHAT THE FOLLOWING PRECAUTIONS ARE
OBSERVED DURING SERVICING TO PROTECT YOUR
EYES AGAINST EXPOSURE TO THE LASER BEAM.
1-WHEN THE CABINET IS REMOVED, THE POWER IS
TURNED ON WITDOUT A COMPACT DISC IN POSITION
ANDTHE PICK-UPISONTHE OUTER EDGETHE LASER
WILL LIGHT FOR SEVERAL SECONDS TO DETECT A
DISC. DO NOT LOOK INTO THE PICK-UP LENS.
2-THE LASER POWER OUTPUT OF THE PICK-UP UNIT
AND REPLACEMENT SERVICE PARTS ARE ALL
FACTORY PRE-SET BEFORE SHIPMENT.
DO NOT ATTEMPT TO RE-ADJUST THE LASER PICK-
UP UNIT DURING REPLACEMENT OR SERVICING.
3-UNDER NO CIRCUMSTANCES STARE INTO THE PICK-
UP LENS AT ANY TIME.
4-CAUTION-USE OF CONTROLS OR ADJUSTMENTS, OR
PERFORMANCE OF PROCEDURES OTHER THAN
THOSE SPECIFIED HEREIN MAY RESULT IN
HAZARDOUS RADIATION EXPOSURE.

WARNINGS (MD)

The AEL (ACCESSIBLE EMMISSION LEVEL) of the laser

power output is less than class 1 but the laser component is

capable

of emitting radiation exceeding the limit for class 1 . Therefore

it is important that the following precautions are observer

dunng

servicing to protect your eyes against exposure to the laser

beam.

1) When the unit case cover is removed and LOADING SW
(SW 1956) is turned on and then PLAY SW (SW 1954
mechanism PWB) is turned on in a few second.

The laser will light for several second to detect a disk.

2) The laser power output of the pickup unit and replacement
service parts are all factory pre-set before shipment.

Do not attempt to re-adjust the laser pick-up unit during
replacement or servicing.

3) Under no circumstances stare into the pickup lens at any
time.

4) If laser optical unit becomes faulty, replace the complete
laser optical unit.

5)CAUTION-USEofcontrols oradjustments,orperformance
of procedures otherthan those specified herein may result
in hazardous radiation exposure.

Laser Diode Properties
Material: GaAlAs
Wavelength: 780 nm
Emission Duration: cpntinu

LASER KLASSE 1
LUOKAN I LASERLAITE
KLASS 1 LASERAPPARAT
LASER TfiiDv 1

LASERTRIEDV1

cuss I USER Ptlnnuct
APPAREIL i tutti ttE DLASSE l
thnucto LASER IIE ELISE l

o CAUTION
Use the MD/CD component system only in ac
cordance With the instructions given in this manual
and do not attempt to interfere with the Interlock
Switch or make any other aotustment as this may
result in exposure to hazardous radlatlon.

rr iiiu mm \\X\\Lm)

Rwlutmw \
irirnmini, i

Laser Output: max. 0.6 mW

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ti Mno int mini s i imi i \ tin

Laser Diode Properties
0 Material: GaAlAs
o Wavelength: 785 rim
0 Pulse time: ,,
Read mode: 0 5 mW Continuous ,
Write mode: max 10 mw 0.55 x
min cycle1.SS
Repetition

pus

tiiii it mioiii

VARO !

VARNING! Osynlig laserstralning nar denna del ar oppnad oc

Avattaessa ja suojalukitus ohitettaessa olet alttiina nakymattomalle lasersateilylle. Ala katso sateeseen.

h sparren ar urkopplad. Betrakta ej stralen.

Precaution to be taken when replacing and servicing the
laser pickup.

The following precautions must be observed during servicing
to protect your eyesvagainst exposure to the laser.
Warning of possible eye damage when repairing:

If the AC power plug is connected when the inner cover of
the unit is removed. the laser will light up during focus
access (about 1 second) (Fig. 21).

During this operation, the laser will leak from the opening
between the magnetic head and cartridge holder (Fig. 2-2).
In order to protect your eyes. you must not look at the laser
during repair.

Before repairing, be sure to disconnect the AC power plug.

Figure 2-1
Magnet Head
f Laser Beam

Cartridge Holder

Mechanism
ChaSSis

Spindle Motor
Figure 2-2

Optical pickup