BBK ABS551T Manual de usuario
SERVICE MANUAL
ABS551T
CONTENTS
1. SAFETY PRECAUTIONS 1
2. PREVENTION OF ELECTRO STATIC DISCHARGE(ESD)TO ELECTROSTATICALLY
SENSITIVE(ES)DEVICES 1
4. PREVERTION OF STATIC ELECTRICITY DISCHARGE 3
5. ASSEMBLING AND DISASSEMBLING THE MECHANISM UNIT 4
5.1 OPTICAL PICKUP UNIT EXPLOSED VIEW AND PART LIST 5
6. ELECTRICAL CONFIRMATION 9
6.1 VIDEO OUTPUT (LUMINANCE SIGNAL) CONFIRMATION 9
6.2 VIDEO OUTPUT(CHROMINANCE SIGNAL) CONFIRMATION 10
7. MPEG BOARD CHECK WAVEFORM 11
9. SCHEMATIC & PCB WIRING DIAGRAM 23
10. SPARE PARTS LIST 38
8.2 MT138912
8.3 AM29LV160D 15
8.4 HY57V641620HG 20
3. CONTROL BUTTON LOCATIONS AND EXPLANATIONS 2
5.2 MISCELLANEOUS 8
1.1 GENERAL GUIDELINES
1. When servicing, observe the original lead dress. if a short circuit is found, replace all parts which have
been overheated or damaged by the short circuit.
2. After servicing, see to it that all the protective devices such as insulation barrier, insulation papers
shields are properly installed.
3. After servicing, make the following leakage current checks to prevent the customer from being exposed
to shock hazards.
Some semiconductor(solid state)devices can be damaged easily by static electricity. Such components
commonly are called Electrostatically Sensitive(ES)Devices. Examples of typical ES devices are integrated
circuits and some field-effect transistors and semiconductor chip components. The following techniques
should be used to help reduce the incidence of component damage caused by electro static discharge(ESD).
1. Immediately before handling any semiconductor component or semiconductor-equipped assembly, drain
off any ESD on your body by touching a known earth ground. Alternatively, obtain and wear a commercially
availabel discharging ESD wrist strap, which should be removed for potential shock reasons prior to
applying power to the unit under test.
2. After removing an electrical assembly equipped with ES devices,place the assembly on a conductive
surface such as alminum foil, to prevent electrostatic charge buildup or exposure of the assembly.
3. Use only a grounded-tip soldering iron to solder or unsolder ES devices.
4. Use only an anti-static solder removal device. Some solder removal devices not classified as anti-static
(ESD protected)can generate electrical charge sufficient to damage ES devices.
5. Do not use freon-propelled chemicals. These can generate electrical charges sufficient to damage ES
devices.
6. Do not remove a replacement ES device from its protective package until immediately before you are
ready to install it.(Most replacement ES devices are packaged with leads electrically shorted together by
conductive foam, alminum foil or comparable conductive material).
7. Immediately before removing the protective material from the leads of a replacement ES device, touch
the protective material to the chassis or circuit assembly into which the device will be installed.
Caution
Be sure no power is applied to the chassis or circuit, and observe all other safety precautions.
8. Minimize bodily motions when handling unpackaged replacement ES devices. (Otherwise harmless motion
such as the brushing together of your clothes fabric or the lifting of your foot from a carpeted floor can
generate static electricity(ESD).
notice (1885x323x2 tiff)
1. SAFETY PREAUTIONS
2.PREVENTION OF ELECTRO STATIC DISCHARGE(ESD)TO
ELECTROSTATICALLY SENSITIVE(ES)DEVICES
1
Front panel illustration
23
FUNCTION button
8
3VOL- button
5
7OPEN/CLOSE button
Glass
12
678
6IR sensor
PLAY/STOP button
9
BAND button
PREV button
10
TUNING<< button
NEXT button
11
TUNING>> button
1
9 10 11 12
4
5Display window
4VOL+ button
2Channel Switch Button
POWER button
1
Component video/Y Pb Pr out terminal
5
2
Video out terminal
3
4
Optical out terminal for
digital audio
7External audio in terminal 1
6
S-video
Rear panel illustration
Coaxial out terminal for digital audio
Front amplifying audio out terminal
8SCART Out jack
Side panel illustration
2
MIC jack
Headphone jack
AM antenna input terminal
Card reader port
3
4
5
FM antenna input terminal
9
9I-LINK out terminal
2
348
567
1
2
1
3
4
5
1
2
The laser diode in the traverse unit (optical pickup)may brake down due to static electricity of clothes or human
body.Use due caution to electrostatic breakdown when servicing and handling the laser diode.
4.1.Grounding for electrostatic breakdown prevention
Some devices such as the DVD player use the optical pickup(laser diode)and the optical pickup will be damaged
by static electricity in the working environment.Proceed servicing works under the working environment where
grounding works is completed.
4.1.1. Worktable grounding
1. Put a conductive material(sheet)or iron sheet on the area where the optical pickup is placed,and ground the
4.1.2.Human body grounding
1 Use the anti-static wrist strap to discharge the static electricity from your body.
4.1.3.Handling of optical pickup
1. To keep the good quality of the optical pickup maintenance parts during transportation and before
installation, the both ends of the laser diode are short-circuited.After replacing the parts with new ones,
remove the short circuit according to the correct procedure. (See this Technical Guide).
2. Do not use a tester to check the laser diode for the optical pickup .Failure to do so willdamage the laser
diode due to the power supply in the tester.
4.2. Handling precautions for Traverse Unit (Optical Pickup)
1. Do not give a considerable shock to the traverse unit(optical pickup)as it has an extremely high-precise
structure.
2. When replacing the optical pickup, install the flexible cable and cut is short land with a nipper. See the
optical pickup replacement procedure in this Technical Guide. Before replacing the traverse unit, remove
the short pin for preventingstatic electricity and install a new unit.Connect the connector as short times as
possible.
3. The flexible cable may be cut off if an excessive force is applied to it.Use caution when handling the cable.
4. The half-fixed resistor for laser power adjustment cannot be adjusted. Do not turn the resistor.
safety_3 (1577x409x2 tiff)
sheet.
3
4.PREVENTION OF STATIC ELECTRICITY DISCHARGE
5. Assembling and disassembling the mechanism unit
4
5.1 OPTICAL PICKUP UNIT EXPLOSED VIEW AND PART LIST
5.2 MISCELLANEOUS
5.2.1 Protection of the LD(Laser diode)
Short the parts of LD circuit pattern by soldering.
5.2.2 Cautions on assembly and adjustment
Make sure that the workbenches,jigs,tips,tips of soldering irons and measuring instruments are
grounded,and that personnel wear wrist straps for ground.
Open the LD shortlands quickly with a soldering ironafter a circuit isconnected.
Keep the power source of the pick-up protected from internal and external sources of electrical
noise.
Refrain from operation and storage in atmospheres containing corrosive gases (such as H2S,SO2,
NO2 and Cl2)or toxic gases or in locations containing substances(especially from the organic silicon,cyan,
formalin and phenol groups)which emit toxic gases.It is particularly important to ensure that none of the
above substances are present inside the unit.Otherwise,the motor may no longer run.
8
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