Jim — Thanks from the future for these wonderfully detailed instructions. I just used to them to attempt a repair on a 1999 iMac which would almost always fail to eject.
It was partial success in my case. About half the time I'll get a complete ejection now, and the other times the disc comes out just enough to grab it and pull it the rest of the way. I think my biggest problem isn't worn rollers, but rather that the rubber rollers aren't snug on the metal dowel and they sometimes spin freely. Best, Fred On Wednesday, March 8, 2006 at 6:08:19 PM UTC-8, Jim Scott wrote: > > > On Mar 8, 2006, at 2:05 PM, Thunder 1 wrote: > > > > I will be cracking the case and extracting the CD from the slot- > > loading > > drive, and will also attempt to clean the rollers(?) on the drive. > > I've downloaded > > a file to guide me in tearing the computer apart and putting it back > > together > > again. I figure that as long as I'm taking this baby apart, I will > > check/replace > > other items at the same time (RAM, Battery). A few questions that I > > would > > like answered first, if anyone can help: > > > > 1. What is the nominal output voltage of the battery? Suggested > > replacement voltage? > > (I know I saw answers to this question somewhere on some list a while > > back, but can't > > seem to find the link ...). If I need to replace it, any particular > > type/brand/store I should > > look at? > > > > 2. The CUDA switch: What is it and what does it do, exactly? Do I need > > to reset > > the CUDA before putting my iMac back together again? > > > > Bill, > > 1. It's a 1/2 AA battery, 3.6 V nominal output. A new one will test > out at about 3.7 V. Any brand 1/2 AA with 3.6 V nominal output will > work. Radio Shack carries them, and all kinds of vendors sell them > online as "computer clock batteries". > > 2. Once you get the bottom cover and the perforated shield off, > you'll be looking straight at the logic board. The CUDA button is > just below the battery and on line with the RAM slots on the left > side of the board. On all 350-700 G3 iMac logic boards I've seen, > it's a tiny black button in a very small silver case. It's always a > good idea to push the CUDA button after replacing the PRAM battery, > or any component. It resets the logic board to factory defaults, and > causes the logic board to identify every component on first reboot > after a reset. This comes in very handy when you replace a hard > drive. Replacing the PRAM battery almost does the same thing, but it > doesn't reset the logic board. > > 3. You'll need to disconnect the IDE cable from the logic board, and > the power cable from the hard drive. Remove the 4 screws holding the > HD/CD drive carrier to the aluminum divider panel and remove the > carrier. Pay attention to how the CD drive comes out of the carrier > after you remove the 4 screws that hold it in place. Use pieces of > marked masking tape to help you get everything oriented properly on > assembly. > > 4. I've taken apart quite a few CD/DVD drives in slotload iMacs. It's > really very simple to do. First, remove the two screws holding the CD > drive IDE adapter to the CD case at the back. Then remove the two > tiny brass-colored screws, one on each corner near the front of the > case on the sides. You'll need a very small Phillips screwdriver with > a fat handle to get the screws out. Don't strip the heads! With the 4 > screws out, gently use a thumbnail to pry the top cover apart from > the bottom of the CD casing at the very front on each side. Voila! > The top cover comes up and off in a smooth lifting motion toward the > back of the CD drive. Note how the three projections fit into slots > at the back. > > Set aside the cover. Now comes the tricky part. In order to get at > the split and tapered drive roller that injects and ejects CDs, you > must disconnect two very tiny springs on either side of that metal > cover above the roller. I use a very tiny jeweler's slot screwdriver. > I slide it into the top loop where the spring fits into a notch in a > black plastic; I gently lift the spring and slide it off the catch. > Once both sides are free, I raise the metal piece a bit and pull it > out of slots on either side. > > There are all kinds of recommendations for cleaners, most with the > words "rubber rejuvenator" or similar descriptions in them. I use a > commercial product called "Goof Off", which is found in just about > any hardware store. I open a window for ventilation because the > stuff's pretty potent-smelling. Using as lint-free a cloth as I can > find (usually a small piece of old T-shirt), I rotate each piece of > the split rubber roller with a finger while wiping off the embedded > lint, dust and who knows what until the roller is nice and black > again and somewhat "tacky". Wipe off the rectangular felt piece on > the underside of the assembly you removed; it keeps CDs from > contacting metal as the roller pulls the disks inside. Then I let > everything dry. > > Blow out the rest of the inside of the CD with compressed air, or > just with lung power. There's rarely any dust inside, in my > experience. You can gently dust off the laser lens with a small paint > brush while you've got the case open, or you can use one of those > commercial CDs with a built-in lens cleaning brush. > > Reassembly is the reverse of disassembly. Take it slow and easy, > being careful not to squeeze the easily bendable metal case halves > together. And do not force anything. The toughest part is getting the > two springs back on. Do it a few times and you'll get the hang of > using the tiny screwdriver to hook the spring loop in place. > > After reassembly, make sure the white plastic arms are free to > move aside when a CD is inserted. If you can push a CD about a third > of the way in with very little pressure, you've got it right. If you > can't get it to go in and feel resistance from those moving plastic > arms, stop. Take the cover off and make sure those arms move easily, > then reassemble and test again. You don't want to get the iMac back > together and find a CD won't go in the slot, like I did the first time. > > This procedure has enabled me to return a number of CD/DVD drives to > nice, smooth inject/eject cycles, and also has cured system freezes/ > crashes caused by laser lenses that looked clean but had just enough > dust on them to cause misreads. However, I've found a couple of CD/ > DVDs with lots of use that were almost cured, but still had some > symptoms. The rubber rollers had worn internally through use past the > point of being able to grip a disk tightly enough for consistent > injection/ejection. YMMV, as they say. > > Good luck and I hope this helps take some of the mystery out of the > process. > > -- Jim Scott > > > -- You received this message because you are a member of the iMac Group, a group for those using Apple iMacs and eMacs. The list FAQ is at http://lowendmac.com/imac/list.shtml and our netiquette guide is at http://www.lowendmac.com/lists/netiquette.shtml To post to this group, send email to imaclist@googlegroups.com To leave this group, send email to imaclist+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/imaclist --- You received this message because you are subscribed to the Google Groups "iMac Group" group. To unsubscribe from this group and stop receiving emails from it, send an email to imaclist+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
