MADE BY Sarvaiya Pratik

 Two types of failure  Problems in CD player

 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

 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.  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.  Bad/heat sensistive electronic components.  Bad or missing optical pickup shield ground

o Problem: Pickup attempts to reset past inner track. Possible causes: o Dirty or defective limit switch, bad connections to it, or its electronics. o Broken parts preventing limit switch from being activated. o Tracking servo out of adjustment or faulty. o Microcontroller or logic problems

 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: CD player ignores you. Possible causes: ◦ Bad connections to one or more buttons or sets of buttons. ◦ Microcontroller failed to reset properly. ◦ Missing/bad voltages from power supply. ◦ Defective microcontroller or other logic.

 Problem: Disc spins in wrong direction or overspeeds and is never recognized. Possible causes: ◦ Disc loaded upside-down. ◦ Dirty, scratched, or defective disc. ◦ Dirty or damaged objective lens. ◦ Tracking or CLV servo out of adjustment or faulty. ◦ Bad component in optical pickup. ◦ Microcontroller or control logic problems. ◦ Bad connections or defective ribbon cable to optical pickup. ◦ Defective spindle motor including worn bearings.

 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 overheats. Possible causes: ◦ Excessive ambient temperature - sauna or hot stereo components. ◦ Failing/marginal part in power supply, logic, or optical pickup.

 Problem: Repetitive noise at disc rotation rate. Possible causes: ◦ Dirty, scratched, or defective (possibly warped) disc. ◦ Dirty or damaged objective lens, suspension, obstruction, etc. ◦ Loose spindle or foreign material on spindle table. ◦ Disc not firmly clamped. ◦ Bent spindle. ◦ Excessive spindle runout due to worn bearing. ◦ Need for servo alignment. ◦ Weak laser or other component in optical pickup.