CD ROM Presentation

CD-ROM  (an

abbreviation of "Compact Disc read-only memory") is a pre-pressed Compact Disc that contains data accessible

CD ROM CD-ROM -(Compact Disk Read Only Memory ) The standard type of CDROM drive which is now shipped and found in the majority of computers today.

CD-RW CD-RW - (CD Rewritable ) drive which is a popular alternative to the CD-R drive. CD-RW has the capability of being written to at least one thousand times. The drawback with CD-RW discs is with the lower reflectivity of the disc itself can limit the t he readability. readability.

DVD ROM DVD - (Digital Versatile Disc ) New standard released in 1995 which originally was called Digital Video Disc and later changed to Digital Versatile Disc. DVD offers an initial storage capacity of 4.7GB (of digital information on a single-sided, single-layer disc the same diameter and thickness of a current CD-ROM

DVD WRITER DVD - (Digital Versatile Disc ) New standard released in 1995 which originally was called Digital Video Disc and later changed to Digital Versatile Disc. DVD offers an initial storage capacity of 4.7GB (of digital information on a single-sided, single-layer disc the same diameter and thickness of a current CD-ROM

COMBO DRIVE

Recordable CD

ReWritable CD

Typically up to 700 MB (up to 80 minutes audio)

Physical size

 Audio Capacity

CD-ROM Data Capacity

Note

12 cm

74-80 min

650-703 MB

Standard size

8 cm

21-24 min

185-210 MB

Mini-CD size

6 min

55 MB

“Business card:

size

Mini CD

CD-ROM Disc  A CD can stores 74 or 80 minutes of high fidelity audio and has a capacity of 682 MB (74-minute disc) or 737 MB (80-minute disc).

Short for  Compact Disc-Read Only Memory, CD-ROM drives are CDPlayers inside computers that can have speeds in the range from 1x and beyond, and have the capability of playing audio CDs and computer data CDs. Below is a picture of the front and back of a standard CD-ROM drive.

Removing the covers The first step is to remove the four  retaining screws from the bottom of the drive. With those screws out, the bottom metal cover  should easily slip off, although you may have to press in on the two tabs. (click on any picture for a close-up view)

1

This leaves the most challenging step next; removal of the front bezel and top metal cover. cover. The following following three images provide provide close-ups of the tabs which hold everything together (on my cdrom model anyway). Study these so you can see how they work work and where they are, as you they will be mostly hidden from view until you get it apart.

 At this point the tabs are the only thing holding it together, together, there are no screws left. Note that with the tray closed the door  will hold the front plastic bezel pretty solidly in place. Do not attempt to forcibly remove the bezel or pull out the door at this time. But you will will need to depress depress the tabs on the bezel (one on each side and one hidden on the top) and pull slightly forward on the bezel to unhook it from the metal cover. You will also need to gently pry the tabs on the metal cover which slide just under the top edge of  the bezel so they are no longer under the bezel (as in the picture).

Use patience during this operation, as you do not want to break the bezel or the plastic tabs on it. Also be very careful ifif you use any prying tools, as you may scratch scratc h the bezel and can very easily apply too much force so that you break it; I did not use any prying tools (just a small blunt blade blade to depress the tabs). I found that pulling up the rear portion of the metal cover first allowed me to finally dislodge everything. everything. Just take your time and be gentle.

One very important important note of caution. See the picture above...that's the CDROM laser lens lens mechanism. mechanism. It is extremely sensitive! sensitive! Do not touch it, do not bump it, do not move it, and by all means do not allow anything to scratch it. You may want to temporarily tape a small piece of felt or cotton cloth over it to protect it.

Removing the circuit board Now we need to remove the circuit board as we need to get underneath it to dislodge and remove the tray tray. The first thing is to unhook all the cables. On mine, there were three flat ribbon cables and two soldered soldered wires wires connected connected to the ejection motor. The ribbon cables will slide straight out of the connector once you s lide the locking clamp open. open. Do be very gentle with the ribbon cable itself, it is very delicate. If you have the locking clamp opened properly properly the cable shold pull out with very little force (this is good, because you'll also have to push it back in when you assemble everything later).

I did not remove the two motor wires, although I could have unsoldered them if necessary necessary.. In my case though, I could just fold the board over being careful not to pull on the motor wires. Note that the curcuit board itself is just held in place with four small tabs and is very easy to remove (yours may have small screws).

Finally I have the board off and folded out of the way (only connected by the two motor wires). Remember, take is slow when pulling off the board. You may have accidentally left a wire of cable connected to the board someplace and you don't want to break any of  the wires. Also it should go without saying, try not to touch any of  the chips or electrical connections and use static electricity grounding techniques.

Removing the tray We now have the mechanical mechanical tray ejection mechanism exposed. exposed. In this case a plastic slider is what what "locks" the door in in place. It is also what is responsible for clamping the spindle motor down on a CDROM and lowering the laser so it is just barely off the surface of  the disk. By manually sliding sliding the plastic level level as shown in the following two pictures, the tray will become unlocked.

It should now be fairly easy to pull the tray out as if you were ejecting a disc. As you are are manually manually turning all the motors, pull gently and slowly. It should not take much force, so if you have to pull hard stop and recheck that you have the tray properly unlocked.

The tray will pull out fully until it hits the stops. These stops prevent the tray from comming comm ing all the way out. On my model, there there are are two plastic tabs on either side of the tray which act as the physical stops.

By pulling out on the sides of the drive, the tray is able to slide past the stops and eventually comes all the way out of the drive.

The tray door Notice that the front bezel may still be captive captiv e on the tray. Even if it is not you will still s till want to remove the door face from the tray. tray. There are two very small tabs on on mine. By pressing pressing in on them, them, the door face will slide upwards and off the tray .

Now you you have most everything apart. But look at the door face closely, closely, you'll see a small s mall ring of felt or  foam. This is the dust dust seal and it will probably be glued in place and can not be removed without destroying it. When painting the door face you want to protect this seal with tape so you don't paint it.

 Also on the tray you may have four small nylon skid plates. These help protect the CDROM from rubbing against the tray and scratching it. If your tray has these, you will will want to remove them and avoid painting the nylon skid plates.

 And finally, finally, the underside of the tray should have a row of gear  teeth which the ejection motor drives.  Avoid painting painting these teeth, teeth, and also avoid reoving any lubrication (if  any) which may be on those teeth.

 At last Finally I have the drive disassembled enough to allow for a proper paint job.