Sharp DV-760X User manual

1
SX9Q5DV-760X/
SERVICE MANUAL
In the interests of user-safety (Required by safety regula-
tions in some countries) the set should be restored to its
originalconditionandonlypartsidenticaltothosespecified
be used.
SHARP CORPORATION
Page
1. IMPORTANT SAFEGUARDS AND PRECAUTIONS ......................................................................1-1
2. FEATURES/3. SPECIFICATIONS ..................................................................................................2-1
4. PART NAMES ................................................................................................................................. 4-1
5. MAINTENANCE CHECK ITEMS AND EXECUTION TIME............................................................ 5-1
6. DISASSEMBLY AND REPLACEMENT OF MAIN PARTS............................................................. 6-1
7. EXPLANATION OF MECHANISM ..................................................................................................7-1
8. OPERATION OF PICKUP...............................................................................................................8-1
9. TEST MODE ................................................................................................................................... 9-1
10. TROUBLESHOOTING ..................................................................................................................10-1
11. IC FUNCTION LIST....................................................................................................................... 11-1
12. SEMICONDUCTOR LEAD IDENTIFICATION ..............................................................................12-1
13. WIRING DIAGRAM ....................................................................................................................... 13-1
14. BLOCK DIAGRAMS ......................................................................................................................14-1
15. SCHEMATIC DIAGRAMS .............................................................................................................15-1
16. PRINTED WIRING BOARD ASSEMBLIES...................................................................................16-1
17. REPLACEMENT PARTS LIST......................................................................................................17-1
18. PACKING OF THE SET ................................................................................................................18-1
CONTENTS
MODEL
DV-760X
DV-760X
DVD VIDEO PLAYER
SERVICE MANUAL DVD VIDEO PLAYER MODEL DV-760X

DV-760X
1. IMPORTANT SAFEGUARDS AND PRECAUTIONS
1-1

DV-760X
2. FEATURES
2-1
• Plays DVD, video CD and CD (Digital Audio) discs
• Built-in Dolby Digital decoder supporting Dolby Pro Logic*1 decoding and Virtual Surround
• For the audio on a DVD disc recorded in MPEG Audio Version 2.0 multi channel (5.1ch)
• New Digital Gamma correction and New Digital Super Picture functions
• Separate colour component output connectors (Y, PB(CB) and PR(CR))
• DTS*2 AUDIO DECODER (DIGITAL THEATRE SYSTEM)
*1Manufactured under license from Dolby Laboratories. "Dolby", "Pro Logic" and the double-D symbol are trademarks of
Dolby Laboratories.
*2 "DTS" and "DTS Digital Surround" are trademarks of Digital Theater Systems, Inc.
3. SPECIFICATIONS
Signal System: NTSC/PAL
Video output: Output connector: Pin-jack
Output level: 1 Vp-p (75Ω)
S video output: Y output level: 1 Vp-p (75Ω)
C output level: 0.30 Vp-p (75Ω)
Output connector: S connector
Component colour output: Y output level: 1 Vp-p (75Ω)
PB(CB) output level: 0.525 Vp-p (75Ω)/75% colour
PR(CR) output level: 0.525 Vp-p (75Ω)/75% colour
Output connector: Pin-jack
Audio output: 5.1ch output: Front L/R, surround L/R, centre and subwoofer
5ch output: Front L/R, surround L/R and center
Output connector: Pin-jack
Output level: 2 Vrms (1 kHz, 0 dB)
Digital audio I/F: Optical digital output: Optical connector
Audio output: Coaxial digital output: Pin-jack
Headphone output: Output connector: Standard jack
Video signal horizontal resolution: 500 lines (DVD)
S/N ratio: 60 dB (DVD)
Audio signal frequency characteristics: For DVD linear PCM playback:
4 Hz to 22 kHz (48 kHz sampling)
4 Hz to 44 kHz (96 kHz sampling)
CD playback: 4Hz to 20 kHz (EIAJ)
(MPEG Audio 1/2)
S/N ratio: CD: 105 dB, 1 kHz (EIAJ)
Dynamic range: DVD linear PCM: 94 dB (EIAJ)
CD: 94 dB (EIAJ)
Total harmonic distortion ratio: CD: 0.005% or less (EIAJ)
Operating temperature: 5°C to 40°C
Storage temperature: –20°C to 55°C
Power supply : 220 V to 240 V AC, 50/60 Hz
Power consumption: 16 W
Dimensions: 430 mm × 351 mm × 97 mm (W × D× H) (Including attachments)
Weight: 3.8 kg
Specifications are subject to change without notice.
Weight and dimensions are approximate.
Digital Output
·Thedigitaloutputformat(opticalorcoaxial)usedinthisDVDplayerislinearPCMaudiosamplingat44.1kHz or 48 kHz.
Linear PCM sound for DVD video discs sampled at 96 kHz cannot be output digitally.
Check the disc jacket for information on the audio sampling used.
3-1. ACCESSORIES
Accessories: Video/audio cord x 1, UM3 battery x 2,
Remote Control Unit x 1, S-Video cord x 1

DV-760X
For details on the use of each control.
4. PART NAMES
4-1

DV-760X
5. MAINTENANCE CHECK ITEMS AND EXECUTIONTIME
Parts Maintained 1,000 hrs. 2,000 hrs.
Pickup
Spindle Unit
Sled Motor
Loading Motor
Belt
Note : Part Replacement
: Cleaning
(For cleaning, use a lint-free cloth danpened with pure isopropyl alcohol.)
Use the following table as a guide to maintain the mechanical parts in good operating condition.
CARES WHEN USING THE PICKUP
1. The laser light having wavelength 650 nm is emitted from the objective lens. BE CAREFUL SO THAT THE LASER
LIGHT DOES NOT ENTER DIRECTLY INTO YOUR EYE.
2.Thesemiconductorlasermaybeeasilydamagedbyelectrostaticcharges.Whenhandlingthepickup,takecaresothat
the electrostatic charge is not generated.
3. The semiconductor laser may be easily damaged by overcurrent. Use the power supply unit which does not give any
spike current when the power is turned on and off.
4. Carefully remove the dust and dirt from the objective lens with the lens blower.
When handling the objective lens, take due care so that it is not contaminated with fingerprint, etc. If the objective lens
is contaminated, impregnate the cleaning paper with a small quantity of solvent (isopropyl alcohol), and gently wipe to
clean.
5. The ozone layer depleting components (ODC) are not used in the production process for the product.
MECHANICAL PARTS REGUIRING PERIODICAL INSPECTION
5-1

DV-760X
6. DISASSEMBLY AND REPLACEMENT OF MAIN PARTS
6-1. DISASSEMBLY
1.Remove five screws (A), and remove the cabinet.
Note: When assembling it, tighten the screws in
order of 1 - 2 .
(Because the set may rise a little by tightening
the screws.)
6-1
17.Remove five screws (T) which install the volume
PWB of the front panel.
18.Remove six screws (U) which install the display
PWB.
19.Remove six screws (V) which install the operate
PWB.
*The spacer and insulation seat under the indication
tube of (W) are bonded with both-side sticking tape.
7.Disconnect the lead lines (F) and (G) and (H) from
the main PWB under the mechanism.
8.Remove three screws (J) on both sides of the termi-
nal angle frame.
9.Remove three screws (K) which install the terminal/
power PWB.
10.Removethreescrews(L)whichinstalltheterminal
block.
11.Remove three screws (M) of the display PWB.
12.Remove four screws (N) of the mecha angle.
13.Remove one screw (P) of the mecha angle.
14.Remove two screws (Q) of the decorative leg.
15.Push out the middle pin (R) of the setting leg in the
direction opposite to insertion. (Two places)
16.Remove two screws (S) which install the main
PWB under the mechanical unit.
2.Remove two screws (B).
3.Remove three screw (C).
4.Releasethehooksofthefrontpanelattwoplaceson
both sides and at three places on the bottom, and
slide the front panel toward you.
5.Disconnect the connector (D).
6.Removefourscrews (E)whichinstallsthemechani-
cal unit.
Top Cabinet
(A) x2 1(A) 2
(A) x2 1
(D)
(E) x4
(B) x2
(C) x1
Front Panel
(C) x1
(C) x1 Remove it when you remove
a front panel because screw
catch is done with terminal
in the substrate (headphone)
and the angle from the panel.
(L) x3
(K)
(J) x3
(N) x4
(P) (R) x2
(K)
Terminal PWB
(Q) x2
(M) x3
(S)
(S)
(F)
(G)(H)
Mechanism
Main PWB
Volume PWB
(W)
Operate PWB
Display PWB
(V) x6
(T) x5
(U) x6

DV-760X
6-2. REPLACEMENT OF MAIN PARTS
<Disassembling and assembling procedure>
· Removing the tray (emergency ejection)
Removing the tray lock (set state)
VIDEO
Tray Decoration Panel
Insertathinplateintothehatchingpart,slowlymovetheitinthearrowdirectionsothatthetrayismovedoutalittleinthearrowdirection.
Note: In this state the tray cannot be removed completely.
· Drive Unit State
VIDEO
Tray Decoration Panel
Slowly move in the arrow direction, using the screwdriver having a fine head.
<Disassembling and assembling the mechanism chassis>
1. Remove the pickup FPC and loading relay FFC A from the main PWB.
Note: Fit the conductive rubber cap to the front end of pickup FPC (short-circuit).
2. Remove the solder joint of loading relay PWB at drive unit rear side.
1 Sled motor lead wire (Yellow·Orange)
2 IN SW lead wire 2 (White)
3 Spindle motor lead wire (Red·Black)
4 Loading motor lead wire (Red·Black)
5 Remove each lead wire from the claw.
1
1
2
3
4
3
2
4A
B
C
SLmotor 1 SLmotor 2 SW GND SP1 SP2
L motor2
L motor2
Black
Red
Red
Black
White White
Orange
Yellow
Remove the lead wire.
Remove the lead wire.
3. Remove the relay PWB mounting screw B (M2.6S + 6S S tight), and remove the relay PWB C .
Relay PWB
Rear side of moving chassis assembly
Conductive rubber cap
(Earth sponge)
4. Disassembling the mechanism chassis moving chassis assembly
(1) Remove the four M2.6 screws A , and remove the clamped top plate B .
P tight screw
with M2.6 washer
AA
B
(2) Remove the M2.6 screw C .
(3) Holding aslant upward the mechanism chassis moving chassis assembly D in the arrow direction, remove.
Note: The slide rack E must be moved to the left side as shown in diagram.
Take care so that the lead wires, especially the earth sponge G at the pickup FPC F front end, must not beremoved.
Slide rack
Mechanism chassis moving
chassis assembly
P tight screw with
M2.6 washer
G
C
F
E
D
Clamper top
plate rear side
6-2

DV-760X
8. Replacing the Sled Motor
(1) At the rear side of chassis remove the two M1.7 screws A , and remove the motor angle B .
(2) Remove the thrust holding screw C (for easier removing wipe off the thread lock).
(3) Remove the two motor fitting screws M1.4 D , and replace the motor E . Motor is replaced in the state while the worm F is
kept press-fitted to the output shaft.
Note: When installing the motor, take care so that the worm does not damage the ANG B hole.
(4) Screw in the thrust holding screw C , adjust the worm front end clearance to 0 to 0.1 mm, and apply screw lock.
5. Disassembling the loading drive system
(1) Remove the two M2 screws A . (4) Remove relay gear 2 E .
(2) Remove the tray pinion B . (5) Remove the two M1.7 screws F .
(3) Remove the relay gear 1 C together with the (6) Remove the L motor G (with pulley) downward.
timing belt S D .
M2
M1.7
L·Motor Pulley
L·Motor
Timing belt S
Relay
gear1 Relay
gear2
Tray pinion
A
B
E
C
D
G
F
6. Disassembling the mechanism chassis from the moving chassis
(1) Remove the insulator B (2 pcs. at the right side in diagram) parallel in the arrow direction.
(At this time it is better to insert the fine head of screw driver at the ID side of insulator and to move in the arrow direction, which
facilitates removal.)
(2) Remove the mechanism chassis in the arrow direction, pulling upward aslant.
At this time take care so that the insulator C (left side, 2 pcs.) is not damaged. (Do not put at once the mechanism chassis
assembly.)
Insulator
Insulator
Insulator
Insulator
Mechanism chassis
C
B
B
C
7. Replacing the pickup and the spindle motor
Since the pickup optical axis and turntable inclination of DVD are adjusted with higher accuracy than of CD/MD, make a replacement
as a mechanism service chassis ass'y (refer to Parts List).
Thrust holding screw
Apply screw-lock.
M1.4 screw
M1.7 screw
Motor Angle BA
D
Worm F
Sled motor E
C
Mecha chassis Ass'y
6-3

DV-760X
7. EXPLANATION OF MECHANISM
(1)Tray loading mechanism
When the tray loading motor rotates counterclockwise, motion is transmitted to the slide rack D through the intermediate
gear 1 A , intermediate gear 2 B and tray pinion C , resulting in insignificant motion in the arrow direction.
The slide rack is linked with the operating chassis. It lowers the pickup mechanism.
The protrusion of slide rack E is linked with the tray through the groove at the rear side of tray, so that the tray is
pushedaheadalittle.When thetrayispushedout,theslide rack isdisconnectedfromthetraypinion,and at thesame
time the gear at the rear side of tray is connected with the tray pinion, and the tray is pushed ahead.
Whenthetrayispushedoutfully,thesliderackmovesfurtherinthearrowdirectionthroughthe grooveattherear side
of tray. The tray position detection switch F is turned on, and the tray loading motor stops.
When the tray closes the operation is as follows. If the tray OPEN/CLOSE button or tray is pressed and the detection
switch is turned off, the tray loading motor rotates clockwise, so that the tray is retracted. When the detection switch
is turned on again, the tray loading motor stops.
Intermediate gear 2
Intermediate gear 1
Tray pinion
Pawl linked with the groove at the
rear side of tray
This groove is linked with the pawl of
pickup mechanism.
Tray position detection switch
Slide rack
F
D
E
B
C
A
Sled motor
Pickup
Sled pinion
Rack
Pickup
Position detection
switch Spindle motor
E
C
B
A
D
(2)Pickup feed mechanism
When the sled motor A rotates, the rack C moves through the sled pinion B so that the pickup D is moved to the
internal or external periphery.
Whenitismovedtotheinnermostperiphery,thepositiondetectionswitch E ispushedbytherack,sothattheposition
of pickup is initialized.
(3)Disc rotation mechanism
The spindle motor is used to rotate.
IC701 is used to control.
When the spindle motor is replaced, replace the
spindle unit.
7-1

DV-760X
8-3. POLARITIES OF SIGNAL
8. OPERATION OF PICKUP
8-1. CIRCUIT CONFIGURATION OF PICKUP
The pickup unit reads signals from the disk, and the flexible cable is connected to the board. The following signals flow through the
cable.
8-2. EQUIVALENT CIRCUIT OF PICKUP
FO+
TR–
TR+
FO–
ACTUATOR
OSC VOS
LD
PD
VA
VB
VC
VD
Sga
Vraf
Vcc
GND
–
+
–
+
–
+
–
+
HOLOGRAM LASER UNIT
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20 1
TR–
FO+
TR+
FO–
VR
PD
VCC
GND
LD
GND
VOS
NC
NC
Vref(VCC/2)
VA
VC
Sga
GND
VB
VD
(NC)
Power adjust
HIGH-FREQUENCY CONVOLUTION
Focus When electric current is flowed
FO+, FO- from FO+ to FO-, the lens comes
to near the disk.
Tracking When electric current is flowed
TR+, TR- from TR+ to TR-, the lens goes
toward the outer circumference.
Gain switching DVD one Layer High gain
Sga DVD two Layer Sga : +5V
CD
8-4. SIGNALS OF PICKUP
8-4-1. Tracking drive signal (TR+, TR-)
The signal drives the tracking servo mechanism which projects the beam on the track by moving the objective lens (OL) to the outer
or inner circumference (at a right angle against the track) of the disk.
2-focus objective lens
Actuator assembly
Monitor Diode
Basic Structure of Laser Diode
Laser Diode
LD PD
8-1
8-4-2. Focus drive signal (FO+, FO-)
The signal drives the focus servo mechanism which aligns the focus on the pit of the disk
by elevating OL (vertically against the disk surface.)
The VR terminal is connected to GND.
8-4-3. Monitor Diode (PD)
Since the laser diode largely varies output of the laser light even if the flowing current is slightly varied, the projection
light is detected with the monitor diode to control the laser light to be equally output.
Since the current varies on the monitor diode according to the intensity of the received light of the laser diode, the drive current of
thelaserdiodeisreducedifthecurrentofthemonitordiodeincreases.Onthecontrary,thedrivecurrentofthelaserdiodeisincreased
if the current of the monitor diode decreases.
As the projection light of the laser diode becomes stronger, the current of the monitor diode increases to increase the current which
flows into the monitor diode output (PD). This is input to the pin 44 of IC303 and is compared with the reference voltage to control
the drive current of the laser diode.
The circuit is called ALPC (Automatic Laser Power Control).
8-4-4. Laser diode drive current control (LD)
Power supply to drive the laser diode
8-4-5. High-frequency convolution module power supply (VOSC)
The high-frequency convolution imposes the high-frequency signal on the DC current to impose the high frequency on the drive
current of the laser. Thus, the interference of outgoing light and reflected light is prevented.
8-4-6. HF Signal (VA, VB, VC, VD)
Signals recorded in the disk When the quantity of laser light increases, the current shown in
figure increases and the PD terminal voltage rises.
IC303 is used to control. The LD terminal voltage lowers, and
the quantity of light reduces. (IC303 is actuated by voltage
input.)