UJ-846...How to kill an iMac in one easy lesson
Many Macs have optical drives that are slot-loaders, drives into which you slide a disc and then it gets pulled in the rest of the way. All MacBooks, MacBook Pros (MacBooks
Pro?), G4 iBooks, some G3 and all G5/Intel iMacs have these drives.
Some of the above units have a little switch hidden at the right end of the slot that triggers the eject function but Matshita (Panasonic) has eliminated this switch from the UJ-846 (SuperDrive) model used in the G5 and Intel iMacs. I believe this drive is also used in the MacBooks and MacBook Pros.
I mention this eject switch because the lack of it just cost Apple about $250 in parts and labor to replace the optical drive in my Intel iMac. Here's why:
I started burning a CD in iTunes and realized I was burning a data CD rather than an audio CD (see the iTunes prefs for these choices) so I canceled the burn using the little x at the right end of the iTunes burn progress bar. The burn stopped in a few seconds but the CD neither mounted on the Desktop nor was ejected.
I pressed the keyboard's Eject key...no response.
I quit iTunes, launched Toast, and selected the Eject Disc menu item...Toast responded that no disc was in the drive.
So what's the next thing you would try?
Of course! Restart and hold down the mouse button which would eject any optical media, right? I did so. However, the disc did not eject and, in fact, the iMac was attempting to
read that optical disc. Obviously, it could not because the disc contained no boot data (it was a failed-burn data disc with, at most, only a few megabytes of garbage on it).
Nevertheless, there sat my iMac with a grey screen and no Apple logo nor a spinning sunburst.
So I held in the power button to shut off the iMac and restarted again but, this time I held down the Option key. This is supposed to bring the Mac to a blue screen showing
all bootable volumes and, from which, one may press the Eject key to eject optical media. However, holding down the Option key did not work and here we were again with the grey
screen and the optical drive making noises trying to read the bad CD.
So I tried zapping the PRAM by restarting and holding down Command-Option-P-R but, again, the iMac went right to the optical drive and ignored all keyboard input.
Restarted again and held down the "T" key to initiate FireWire Target Disk mode. Same result: No keyboard input was recognized; reading the optical drive took precedence.
A call to AppleCare ensued and they scheduled a visit where the tech picked up my iMac, replaced the optical drive with a new one of the same model, and returned it to me later that day.
One thing the tech did (and I didn't know this until later) was to extract the CD from the old drive and insert it into the new drive while the iMac was booted and sitting in the Finder! As expected, the disc did not appear on the desktop and the Eject key had no effect. He thought he might have really fubar'd this situation again but, after about 10 minutes, the Finder complained that it couldn't read the disc and offered to eject it ( whew).
So what have I learned from this situation?
1. Had Apple simply had the eject switch in this optical drive, I could have reached it with a paper clip and resolved the problem without involving AppleCare.
2. If you get into a situation where an optical disc won't mount (and you don't have an eject switch in your optical drive), wait ten minutes or even more for your Mac to realize it doesn't recognize it and will offer to eject it for you! Do not simply restart and think that
depressing the mouse button at boot time will eject that recalcitrant disc.
Obviously this optical drive (and maybe my Intel iMac) requires a firmware update to address this issue. Whatever optical drive Apple provides with its Macs should absolutely, positively eject its optical media when the mouse button is depressed upon startup. The fact that it failed to do so indicates a major problem that needs addressing immediately
Finally, any slot-loading optical drive should have the manual eject button. This is a classic case of "penny-wise and pound-foolish".
Be careful out there, folks!
Barry
Pro?), G4 iBooks, some G3 and all G5/Intel iMacs have these drives.
Some of the above units have a little switch hidden at the right end of the slot that triggers the eject function but Matshita (Panasonic) has eliminated this switch from the UJ-846 (SuperDrive) model used in the G5 and Intel iMacs. I believe this drive is also used in the MacBooks and MacBook Pros.
I mention this eject switch because the lack of it just cost Apple about $250 in parts and labor to replace the optical drive in my Intel iMac. Here's why:
I started burning a CD in iTunes and realized I was burning a data CD rather than an audio CD (see the iTunes prefs for these choices) so I canceled the burn using the little x at the right end of the iTunes burn progress bar. The burn stopped in a few seconds but the CD neither mounted on the Desktop nor was ejected.
I pressed the keyboard's Eject key...no response.
I quit iTunes, launched Toast, and selected the Eject Disc menu item...Toast responded that no disc was in the drive.
So what's the next thing you would try?
Of course! Restart and hold down the mouse button which would eject any optical media, right? I did so. However, the disc did not eject and, in fact, the iMac was attempting to
read that optical disc. Obviously, it could not because the disc contained no boot data (it was a failed-burn data disc with, at most, only a few megabytes of garbage on it).
Nevertheless, there sat my iMac with a grey screen and no Apple logo nor a spinning sunburst.
So I held in the power button to shut off the iMac and restarted again but, this time I held down the Option key. This is supposed to bring the Mac to a blue screen showing
all bootable volumes and, from which, one may press the Eject key to eject optical media. However, holding down the Option key did not work and here we were again with the grey
screen and the optical drive making noises trying to read the bad CD.
So I tried zapping the PRAM by restarting and holding down Command-Option-P-R but, again, the iMac went right to the optical drive and ignored all keyboard input.
Restarted again and held down the "T" key to initiate FireWire Target Disk mode. Same result: No keyboard input was recognized; reading the optical drive took precedence.
A call to AppleCare ensued and they scheduled a visit where the tech picked up my iMac, replaced the optical drive with a new one of the same model, and returned it to me later that day.
One thing the tech did (and I didn't know this until later) was to extract the CD from the old drive and insert it into the new drive while the iMac was booted and sitting in the Finder! As expected, the disc did not appear on the desktop and the Eject key had no effect. He thought he might have really fubar'd this situation again but, after about 10 minutes, the Finder complained that it couldn't read the disc and offered to eject it ( whew).
So what have I learned from this situation?
1. Had Apple simply had the eject switch in this optical drive, I could have reached it with a paper clip and resolved the problem without involving AppleCare.
2. If you get into a situation where an optical disc won't mount (and you don't have an eject switch in your optical drive), wait ten minutes or even more for your Mac to realize it doesn't recognize it and will offer to eject it for you! Do not simply restart and think that
depressing the mouse button at boot time will eject that recalcitrant disc.
Obviously this optical drive (and maybe my Intel iMac) requires a firmware update to address this issue. Whatever optical drive Apple provides with its Macs should absolutely, positively eject its optical media when the mouse button is depressed upon startup. The fact that it failed to do so indicates a major problem that needs addressing immediately
Finally, any slot-loading optical drive should have the manual eject button. This is a classic case of "penny-wise and pound-foolish".
Be careful out there, folks!
Barry
Intel iMac 20" / MacBook, Mac OS X (10.4.6), Where the h*** did all these firewire drives come from?
