CD Replication Industry Issues

Hi everyone, first post on this forum so please help me if you can!

I work for a company who ship CDs with data on to customers. Recently, we have noticed some of the CDs are corrupted. We send our CD master (burnt in house) to a company to create the glass master and replicate the CD. Some of the disks are fine, but we are finding a lot are being returned as faulty. Cannot seem to find a common CD ROM drive manufacturer which seem to reject these CDs so we are thinking there may be a problem at the replication end of things. However the company are claiming everything is fine. So… I now have the task of looking into this to figure out whats going on (not the greatest task in the world!!) I have been asked to look into the following:

Duplication quality (industry standards and industry error rates)
Media quality (how does different media [not CD-R, the kind of media that the replication company burn on to -but don’t really know what this is] stack up)
Mastering (concepts, tools and error handling)
Tools and test cases for CD testing

Any advice on the kinds of questions I should be asking, or where I should be looking for the answers?

I know this is a long post but it would be great if someone could help!!!

Cheers

The best thing to determine the quality of your burns would be a CAT scanner, you can purchase one from AudioDev: http://www.audiodev.com as their testing methods are about the industry standard. However their equipment is pretty expensive and there are some software applications that give an indication as well. There is Plextools, Kprobe and Nero CD DVD speed. A search on each of these terms will give you many results and a lot to read up :wink:

When the customer returns your CD as faulty, what do they say happens on their PC when trying to read your CD? Here are some common answers:

The CD drive does not recognize that a CD has been inserted.
When trying to run the software on the CD they get read errors.
When trying to copy the CD to their hard drive they get errors.

I assume your CD is ROM data and not audio.

The company that mastered your CDs should have ran a bit to bit compare of the replica CDs and your original CD-R master. Did they provide you with this bit to bit compare report log?

The mastering company will probably have a CD tester like the one from Audio Dev mentioned by DoMiN8ToR. You should ask them for a report from this tester as well. This tester does not do bit to bit compare but it tells the quality of the CDs.

Well, we supply a CRC checker with the disks to check the stored CRC against the calculated one. This is returning a read fail message on some machines, but not on others! So its not even like the CRC is incorrect, it is just not reading the disk (or at least that area of the disk). Hope this info is useful

Are these CDs using any type of copy protection encryptions? We know there has been a problem with many, you remeber the recall of SecuRom.

Sorry for the late reply, but been away recently!

There is no copy protection on the CDs, they just seem to be unreadable on particular users machines. Could this be a problem witht he quality of the original media used to create the galss master, or could it be a problem with the media used for the mass replicated CDs? Or could it be a problem witht the actual data? Any feedback is much appreciated. Thanks again for all the help so far!

The quality of the original CD-R should not be it. If the mastering facility could read it, then no problem. If they could not read it, you would have had to send a replacement. The data on the original could be such that replicas made from it can’t be read by all readers. This is not very normal but it does happen. The quality of the replicas is a good place to look first.

I have been looking into this over the past couple of hours. We have had some tests done on these disks and they appear to read fine on the machine where the testing has taken place, but there seem to be high numbers of E22 errors - the reports also mention LECC which has a count of 1. Are these kinds of errors handled differently by different drives, as we have managed to find common manufacturers that fail on these CDs. However, it gets more complicated when we find that these patterns only occur in Batches (so, different drives will work on some batches and not with others and vice versa - so there does not seem to be some universal answer!!) Thanks again!!