I have fixed my iMac, which was scratching CDs, most evident when I burned a brand new CD, it would not verify and upon inspection was found to have a cluster of scratches. The problem appeared on CDs that were carefully inspected before use.
Disclaimer: The following procedure may not work for everyone. It may not work the first time. If done carefully it should not damage your iMac or your fingers, but both are possible. It could put your warrantee at risk if you really muck it up or if you take it in for an unrelated problem and the tech is having a bad day or you are being obnoxious. Don't call me or Apple if your outcome is an unhappy one.
The problem:
Sharp edges on the shell slot through which a CD is inserted and removed. The sharp edges are actually 90-degree corners cut with uneccesarily high precision,
There are two such edges at the rear of the shell (either of which can scratch the data side of your CD.) You can see and feel the one on the outside (feel carefully, it's sharp!). There's a second edge inside the slot, about 2mm from the first one. Either edge can scratch CDs, but it's the inner one that is the more likely culprit.
The fix:
Dull the sharp edges.
You will need:
A vacuum cleaner with crevice attachment.
A friend to hold the crevice attachment against the slot while you work.
Some unscratched CDs for testing. New ones will work, but you will damage them, so some of those old AOL CDs you have in a drawer are a better choice.
A flashlight, preferably one of those single LED keychain types.
A paperclip. No fancy coating, no plastic. Just a plain steel paperclip.
(Optional) a burnishing blade.
A slightly long fingernail on the thumb of your right hand. It will grow out while you read the rest of this.
Some wood toothpicks of the round variety. Not flat ones. Square might work.
A box of facial tissues, plain (no aloe or similar gunk).
A lamp, located behind the system and on the right side, for viewing test results.
The steps:
1. Eject any CD currently in the drive. Remove it carefully, keeping the back side away from the rear slot and those sharp edges.
2. Shutdown and unplug the system. Everything is done with power off, including testing.
3. Using the flashlight, take a good look into the CD slot. Note the two rear edges, one outside, one inside. Note the little brushlike seal through with a CD must pass. Nothing you do should disturb this seal, so you don't have lots of working room. Between the inside sharp edge and this seal, against the back of the shell, you can see a white material. I think it's plastic. It's not part of the problem, so you don't want to alter it with any of the things you are about to poke around with. One last time, note where the outer and inner edges that you want to dull are located.
4. Start with the outer edge, since it could cut your fingers if you try to do the inner one first. Select a tool (see below). Insert the tool just far enough into the slot that it rests on the edge to be dulled. Start at the top of the slot and drag the tool downward, pressing it against the edge to be dulled. Throughout this process, your friend should be preceding your hand motion with the crevice tool to suck up any metal fragments or blood. You should angle the tool slightly, with the right end a bit toward the rear of the shell, so it rides on the outer edge you are trying to dull.
5. Repeat with the inner edge. This requires that the tool be inserted enought to reach the inner edge, but not so far as to contact the brush seal. Take your time and work carefully. You should angle the tool slightly, with the right end a bit toward the front of the shell, so it rides on the inner edge you are trying to dull.
6. Clean the work area. Use the vacuum alone, then fold a corner onto a facial tissue and insert it as far as possible (short of the brush seal) into the slot and run it up and down. Repeat until it comes out clean. Vacuum again.
7. Test the result. Turn on the lamp behind the system. Take a CD and locate an unscratched area (you can use each test CD several times). Place that area in a 3 o'clock position, as viewed from the front of the system (this will be the last part of the CD to enter the slot) and hold the CD on the outer edge, also in the 3 o'clock position. Carefully insert the CD part way , keeping the trailing edge pulled gently toward you so the CD doesn't contact the rear of the slot. Leave enough of the CD sticking out so you can still grab it with your finger tips. Now lean over the system so you can look down at the back side of the CD. Slowing pull the CD out of the slot, watching the data area. As you pull, gently push the right side of the CD against the back of the slot. If the slot is still sharp or has rough spots, you will see a scratched area emerging from the slot. Make note of where the scratches are; that area needs more work. Repeat until no scratches appear. NOTE: Scratches are more likely to occur when the CD is more than halfway into the slot, i.e. during the first half of insertion or the last half of removal of the CD.
The tools:
This is the order in which I used them. You may want to try something different. I think the toothpick step is essential; the others may not be. It would be interesting to know if toothpicks alone will do the job.
- Paper clip. The idea is that steel is harder than aluminum, so the paper clip should burnish a slight bevel onto the aluminum edge. This worked well for me on the outer edge, less so on the inner. I used a fair amount of pressure and my paperclip cut cut up a bit in the process. Vacuuming is essential. This did bevel the edge a bit, but still left a rought surface.
- Burnishing blade. My blade is flat and about 1/4 inch wide. I tried both running it up and down the slot edge and sawing it in and out while shifting its position vertically from time to time. My impression is that it wasn't leaving a much smoother surface than the paperclip did.
- Thumbnail. I inserted my right thumbnail into the slot so the nail rested on the inner edge and ran it up and down. This did seem to help smooth the surface (and took material off the underside of my thumbnail...).
- Toothpick. I broke off the tapered tip to get to the thicker part of the toothbick so I could apply more pressure. This is what finally did the trick, but I suspect at least the paperclip step was an essential start.
What does it look like when you are finished? Unless you have a 10X magnifier, same as before.
Should you have to do this? Shouldn't Apple have to fix the systems (and put some people in China to work with toothpicks on the new ones)? Sorry, I don't have time to debate that. I have to run out and buy stock in a toothpick company....
Chris Beall
