Avs presentation

TROUBLESHOOTING IN

CD-DVD PLAYER SUB MITED B Y : -

VATSAL BODIWALA : 140083112002 GAURAV MEHTA : 140083112007 Under the Guidance : Prof. Ripal Patel ET department, BVM

GUJARAT TECHNICAL UNIVERSITY

Birla Vishwakarma MahavidyalayaET Department

Content:-

• Definition of Troubleshooting • Troubleshooting in DVD Player• Troubleshooting in CD Player• Flow chart • Comparison Between CD & DVD

Definition Of Troubleshooting:-

Analyse and solve serious problems for a company or other organization. ORTrace and correct faults in a mechanical or electronic system.

Troubleshooting is needed to develop and maintain complex systems where the symptoms of a problem can have many possible causes.

TROUBLESHOOTING IN DVD PLAYER

• A DVD Player is complex set of equipment of having mechanical, optical, & electronics components which are prone to faults.

• Many glitches in the disc may disappear by a simple process of ‘eject, reseat & reinsert’ the disc.

• Incompatibility due to geographical location, although not a fault, will not allow the DVD to work. e.g. TV standard of scanning, colour encoding & decoding, bandwidth, etc.

• A DVD may have aspect ratio of 4:3, but with the player, set for 16:9 ratio, the images would be appear thin & tall in the display.

• Similarly , DVD using MPEG compression may not be audible in the receiver which cannot decode MPEG code.

• When a disc is designed to have provision of ‘Digital Theater System’ (DTS) And the player is not able to produce the DTS, the common fault would be

‘DTS disabled’ on the DVD player.

• Many players have DTS output turned off by default (normal condition by the manufacturer) ; enabling the player for DTS would remove the fault.

Flow chart for troubleshooting a DVD player

Common problems in DVD :-

• Disc being not recognized

• Audible noise

• Erratic tracking

• Sticking or skipping

• For this, cleaning of the lens/disc is the first thing to be done . A soft cloth or paper towel moistened with water , is used to clean the disc & lens

• The disc should be wiped from centre to edge & dried , using a lint-free cloth.

• If DVD player is found totally dead, it may be safely presumed that the electric power is not available to player. Same thing happen with remote control unit .

• Hard failure - door opening/closing problems, disc is not recognized, no sound, unit totally dead.

• Soft failure - skips, continuous or repetitive audio noise, search or track seek problems, random behavior.

• A CD player is an electronic device powered by a universal motor that rotates a flat plastic disc

TROUBLESHOOTING IN CD PLAYER

TWO TYPE:

• Dirty optics - lens, prism, or turning mirror.

• Drawer loading belts - worn, oily, flabby, or tired.

• Sticky mechanism - dirt, dried up/lack of lubrication, dog hair, sand, etc.• Broken (plastic) parts - gear teeth, brackets, or mountings.

• Need for electronic servo adjustments - focus, tracking, or PLL.

• Intermittent limit or interlock switches - worn or dirty.• Bad connections - solder joints, connectors, or cracked flex cable traces.

• Motors - electrical (shorted, dead spot) or mechanical (dry/worn bearings).

• Laser - dead or weak laser diode or laser drive (power) problems.

• Photodiode array - bad, weak, or shorted segments or no power.

• Bad/heat sensistive electronic components.

• Bad or missing optical pickup shield ground

• Problem: Pickup attempts to reset past inner track.

• Possible causes:

• Dirty or defective limit switch, bad connections to it, or its electronics.• Broken parts preventing limit switch from being activated.• Tracking servo out of adjustment or faulty.• Microcontroller or logic problems

PROBLEM IN CD PLAYER

• Problem: CD player is totally dead.Possible causes:

▫ Power outlet, wall adapter, or batteries are dead (as appropriate).

▫ Damage to line or wall adapter cord or plug.

▫ Bad connections or faulty component in power supply (including blown fuse).

▫ Defective microcontroller.

• Problem: CD player is operational but there is no display or partial display.

•Possible causes:

▫ Burned out back-light bulb(s).

▫ Bad connections to display panel (totally dead or erratic).

▫ Bad solder connections on display panel (some segment work).

▫ Bad power supply (EL panel filament, driver voltages).

• Problem: Drawer does not open or close.Possible causes:

▫ Worn, stretched, oily, flabby, belt.▫ Dirty mechanism or gummed up lubrication.▫ Stripped gear or other mechanical damage.▫ Defective motor or bad connections to motor.▫ Bad drawer/eject button.▫ Missing/bad voltages from power supply.▫ Defective microcontroller or other logic.▫ Dealer antitheft lock enabled.

• Problem: CD player or CDROM drive damages CDs.

• Possible causes:

• Broken, bent, or missing part.• Messed up gear timing (mainly cartridge changers).• Other mechanical fault.• Lens hitting CD due to electronic fault or need to adjust focus serv

• Problem: CD player or CDROM drive damages CDs.

Possible causes:

• Broken, bent, or missing part.

• Messed up gear timing (mainly cartridge changers).

• Other mechanical fault.

• Lens hitting CD due to electronic fault or need to adjust focus serv

Compare CD-DVD :-

• Diameter :- Having same diameter

• Numerical aperture :- 0.60 for CD & 0.38 to 0.45 for DVD

• Capacity (per side) :- 650 MB for CD & 4.7 GB (single layer) , 8.5 GB (dual layer)

• Scanning speed :- 1.2 to 1.4 m/s for CD & 3.49 to 3.84 m/s for DVD

• Reflectivity :- 70% minimum for CD 45 to 85% for DVD

• Rotation speed :- 200 to 500 rpm for CD• 570 to 1600 rpm for DVD

• User data rate :- 1.41 Mbps & 11.08 Mbps

• Error correction :- CIRC & RS-PC

• Format overhead :- 252 % & 136 %

References:•R.G.Gupta•Techmax •Google.com

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