To start with, make sure that your CD player is suffering from the problem that this method is designed to fix. This method is designed to fix a misaligned CD read head. The common symptoms of this problem are:
1. You place a CD in the player, and it spins for a bit but never finds the list of tracks on the CD and returns some kind of error. This problem may occur regularly or intermittently.
2. CDs tend to skip frequently, even if they are clean and in good condition.
So if this sounds like your problem, then this method is for you. You should however bear the following in mind: only attempt to fix the CD player if the fault occurs frequently and is really annoying; i.e. if you are thinking of throwing the CD player away. To carry out the repair you will have to open the case. This will certainly render void any warranty the device might have, so if your player is still under warranty, don't open it. Simply return it to the retailer. Finally, for your safety and that of your equipment be sure to disconnect your CD player and remove any batteries at least a half hour before you start work. Finally, although I have had consistent success with this method, everything you do is at your own risk and is your own responsibility. I provide no guarantee of any nature regarding this method.
Your first job is to open up the case of your CD player. This will be more or less difficult depending on the type of device. If you are lucky and have a Hi-Fi separate type device then it will be pretty simple; if you have a mini or midi-system with a built in CD player this could be trickier. Fixing portable CD players (e.g. a Discman) is probably only for the uber-patient as it is likely to be very fiddly. The main thing required here is patience and a methodical approach. As you remove screws put them somewhere safe; line them up in the order in which you removed them, or make notes of what goes where. You may reach a point where you think you have taken all the screws out but you still can't get into the case. Here, patience is still the key. Check under stickers for hidden screws or clips. Try and work out where the case is held together. Use the minimum force possible at all times.
Now, assuming you have managed to get into the case successfully, and have got access to the CD player we can continue. By now you will probably be able to see the CD tray (the bit that holds the disk) and also some kind of arm which hovers over the disk when the tray is closed. There will usually be a small motor for moving the lens over the disk, and attached to this or nearby there is typically a small circuit board.
On this board, or in any case rather close to the read head there can usually be found a small potentiometer (sometimes referred to as a pot). This will usually be a small square component with a plastic disk on top, and this disk will have a slot which is designed to take a small flat head screwdriver. This is what we will be adjusting.
However, before doing this it is advisable to use an indelible marker pen (magic marker) to mark the current position of the Potentiometer, so that it can be returned to its original position if necessary. With this done then we are ready to start fixing your CD player.
This is essentially a trial and error process. You make a small adjustment to the position of the potentiometer, then try the CD player and see if it is improved. In my experience generally only small adjustments (less than plus/minus 30 degrees of rotation) are usually necessary.
Depending on how comfortable you are working with electrical devices there are different ways of going through this trial and error process. If you are unsure of yourself or particularly safety conscious then will probably want to put the case back on the CD player each time you test it because you will probably have to plug it in to do this. However, as you have probably guessed it is not necessary to put all the screws back in.
If you are a little more comfortable with electrical devices, e.g. you're the kind of person who never puts the sides on the case of their PC, then you may want to do the testing without putting the case back on the CD player. Obviously, this requires a good deal more caution, but it also makes the whole process quicker. While the device is plugged in, be sure to touch only the player's play and stop/eject buttons, unplugging the device again before making any adjustments. Be sure to keep hands and tools away from the player's power supply unit (PSU)/transformer (if you don't know how to identify this then you had better close the case between tries). Also be aware that the PSU can store power for some time, so it is advisable to leave the unit unplugged for a while between attempts, and not to touch the PSU.
After a few attempts it should be possible to find a position of the potentiometer (the little adjustable thing with the slot in the top) where the CD player recognises disks again and plays them without skipping. If, this is the case, then congratulations, you've fixed your CD player. Simply put the case back on and you are ready to rock.
http://www.kuro5hin.org/story/2004/3/24/45212/6874
