HELP!!! CDR problem, but it's not scratches! Can anything be done?

[motulist]

Help!!!

I tried to copy all the files off of a CDR full of pictures I burned about a year ago, and most of the files transfer seemingly fine, but some transfer without an error but are actually damaged when I open in an image viewer, and others don't copy at all and fail with a finder error. The ones that open fine are at the beginning of the files listed alphabetically in list view, then around letter J I start to get pictures that transfer slowly but without error but are actually damaged when opened, and then at letter S I get finder copy failures, then around T I start to get slow transfers that complete again.

I've tried reading the disk in 2 different drives, but I get the same problems on the same files in both drive. There are some scratches on the disk, but nothing major, and I've already tried to buff them out with toothpaste, but it had no effect good or bad, so I don't think it's a scratch problem. Is there anything at all that can be done with a CDR that has digital problems (as opposed to mechanical problems like scratches)?

finder error:

The finder cannot complete the operation because some data in "image_100.jpg" could not be read or written. (error code - 36)

When I run Disk Utility it reports the error:

Verifying volume “pictures”
Checking HFS Plus volume.
Invalid B-tree node size
The volume needs to be repaired.

Volume check failed.

Error: The underlying task reported failure on exit (-9972)

1 volume checked
0 HFS volumes verified
1 volume failed verification

When I ran the program Drive 10 it reports:

Report for Volume 'pictures'

Format: Mac OS Extended
Interface: ATA
Capacity: 710.0 MB
Available: Zero KB
Used: 710.0 MB
File Count: 3,214

Unit Ready
Passed
This test determines whether the target device is able and ready to receive commands.

Supply Voltage
Passed
This test checks the power supply voltage level that supplies power to the device.

Diagnostic
Passed
This test initiates a self-diagnostic on the target device. These routines are designed by the drive manufacturer and provide excellent insight into the operational condition of the device.

Rezero Unit
Passed
This test determines the ability of the device to resynchronize and rezero the read/write heads.

Format Check
Passed
This test establishes whether the device was properly formatted during initial setup routines.

Spare Sectors
Passed
This test checks the service tracks to determine whether there are enough spare blocks for block repairs.

Surface Scan
Failed (Error = -4)
The Surface Scan test will scan the disk for bad blocks. Drive 10 can map out the offending blocks so that they are not used in the future.

Media defects cause this test to fail. You should consider backing up the device, reformatting the media, replacing the data, and then testing again.

Seek
Failed (Error = -5)
This test checks the ability of the initiator to position the device heads in preparation for access to a particular logical block on the device.

Damaged system software can sometimes cause the improper operation of disk drives, resulting in invalid error reports. Try running this test again from the Drive 10 CD to verify that a faulty system is not causing an invalid report. If the problem disappears, consider reinstalling your system software.

Sometimes, problems can occur because of a device conflict. While this usually only occurs with older SCSI devices, there is potential for power overdraw on USB and FireWire devices that utilize bus power. If there are any other media devices which can be easily removed, consider re-running the test with only the problematic device installed.

Media defects can also cause drive tests to fail. Run the Surface Scan tests to check for bad blocks on the drive. If none of the above fixes the problem, consider backing up and reformatting the drive.

Volume Structure
Failed (Error = -2)
Drive 10 can scan volumes for problems related to the numerous structures that are necessary for the volumes to operate correctly. If problems are found, Drive 10 can attempt to repair the damage to help reduce the chance of future problems.

If Drive 10 has discovered problems with the volume structure of a volume, allow the program to repair the problem. Quite often these issues are minor, but sometimes they can be indicative of a more serious problem. If the problem persists, consider backing up the device, reformatting the media, replacing the data, and then testing again.

HELP!!!

 

[epochblue]

If the disc is over a year old, it's possible the problems are due to what's called "bit rot." Depending on the quality of the CDR and how the disc is cared for, some discs experience bit rot faster than others.

How was the disc cared for in the last year? In a case away from light, perhaps?

 

[motulist]

It can't be from environmental conditions because they've been kept in a closet and I've just completed burning all 3 or 4 hundred of my old cdr's going back for years onto DVDr and giving them PAR files. And there were only 2 that had a problem, but they are not nearly the oldest ones and they both came from a different time period and different manufacturer.

What could cause that node size error? And do you think that error is actually accurate or is it just an artifact of some other problem with the disk?

 

[Frisco]

You can try copying the bad cd to another cd. Sometimes that has worked for me. Good luck!