Unreadable disk on cd-r's

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Level 1

84 points

Unreadable disk on cd-r's

When I try to insert a burned disk with data on it, I get the message "this computer cannot read the disk" The options it gives me are "ignore" or "eject." I've tried changing the "hostconfig" file in the "etc" folder, as suggested by the support website, but that suggestion was for an older version of OSX. http://docs.info.apple.com/article.html?artnum=106345

After I did that the disk just spun inside the drive, nothing happened at all.

After calling the support line and reinstalling OSX, it still doesn't work. Any ideas?

Note, the drive reads audio cds and dvds fine, and the cd-r's work on my ibook fine, too.

Macbook Pro, Mac OS X (10.4.5)

Posted on Mar 26, 2006 8:35 PM

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Answer 1

Bob Maher

Level 3

680 points

Mar 27, 2006 7:10 AM in response to Rollem

You might want to try this:

Insert the disk. Does Finder even See it?
- - If no, then go to Applications>Utilities>disk utility and find the drive if it is shown. Then click the drive, then the button "initialize".

If the disk is not found in finder or on the list of disks that show up in disk utility, it probably is an unreadable disk on your MBP. I have no idea why, but about the only other thing you can do is eject it and try again. It may be a formatting issue or perhaps requires the original burning software be installed on you MBP. It is also possible, but unlikely, that the MBP simply does not support the type of disk. If you have an external CD/DVD drive (USB or FW400), you might try hooking that up and see if it works. If it does, then I'd say you might have a problem with your built in drive or the drive can't read the type of disk you have.

Bob

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Answer 2

Rollem Author

Level 1

84 points

Mar 27, 2006 2:08 PM in response to Bob Maher

A disk will show up in disk utility, but not in finder. In disk utility, there is no option to initialize the disk, and none of the 4 buttons under "first aid" (repair and verify disk and disk permissions) are clickable.

I got off the phone with apple again, they suggested I reset the "p-rom" using the comand-option-p-r method, which did not solve the problem. She ended by saying it was a compatability issue, which is odd to me since the cds come up fine on an ibook also running 10.4.5.

I just tried burning and reading a test cd, which worked fine, and the computer is also able to read cd-rws, at least the one i tried.

If anybody knows what the hostconfig file SHOULD be for macbooks (in the etc folder), I'd be happy, since the only thing that has changed my situation so far has been doing just that, but using an old hostconfig file for OS 10.1. It did not solve the problem, but the error message did not show up.

Thanks anyone!

Macbook Pro Mac OS X (10.4.5)

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Answer 3

Mar 27, 2006 2:24 PM in response to Rollem

That technote is for a much older OS version. In mine I see a line AUTOMOUNT=-YES- . These drives do seem to be somewhat sensitive in some ways. I'm have an impossible time getting one MacBook to write DVDs at 4x (it's only worked once and on an Apple labeled DVD-R) while another MacBook happily writes 4x no problem.

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Answer 4

Rollem Author

Level 1

84 points

Mar 27, 2006 4:01 PM in response to Brian Caslis

You're right, the file they list in that help page is old. I went back and undid the changes I made since I assume several other functions are affected by that file. My file also has the AUTOMOUNT=-YES- code in it. Can someone confirm my hostconfig file? It reads:

AFPSERVER=-NO-
AUTHSERVER=-NO-
AUTOMOUNT=-YES-
CUPS=-AUTOMATIC-
NFSLOCKS=-AUTOMATIC-
NISDOMAIN=-NO-
TIMESYNC=-YES-
QTSSERVER=-NO-
WEBSERVER=-NO-
SMBSERVER=-NO-
SNMPSERVER=-NO-
SPOTLIGHT=-YES-

This file can be found by opening text edit, and searching for /etc/hostconfig in the spotlight bar,and opening the hostconfig file. I bet the file is actually fine and the problem lies elsewhere, since I've done the reinstall process from my disk and redownloaded the latest 25mb security update.

Can anyone else read wintel-made cd-rs on their MBPs?

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Answer 5

Jun 18, 2006 9:27 AM in response to Rollem

I'm having a similar problem. I have a bunch of old CD-R's that I made on my old G3 tower, witht he Apple Factory Installed CD-R drive. none of them are readable on either my PowerBook G4 or my iBook. I put them in the drive and nothing happens. They don't mount, they don't spiun, they don't get spit back out, they just sit there. Both newer machiens have no trouble reading regular CD's, data CD's from software companies, or DVD's. Just CD-R's that I made 5 years ago and thought all mny data was safe and backed-up.

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