The lens touched the spinning disc - is that really bad?

Hi everyone!

I’ve been using a Plextor 48/24/48A (the Premium’s predecessor) CDRW drive at the office for quite some time, with great results.

I got and external USB 2.0 enclosure recently, and been using the drive in it since. With great results.

One day that I will always curse, the enclosure accidentally got a shock - while I was writing a CDRW with 10x!
When I took the disc out, it had a narrow circular track on it, like made with sandpaper. It seems the lens touched the disc during the write, because of the mechanical shock.

The disc is of course ruined, but this is nothing compared to what my dear Plextor suffered.
I wrote a Traxdata the other day, and the readback data verification gave two errors towards the end of the disc. Except for those two files, the rest reads ok.

Now I don’t have the courage to back up any of my data on CDs, not even to TDKs or Super AZO Verbatims I usually burn.

Luckily for me, I could ask for an extra drive, so a Plextor 712A DVDRW is coming. When it arrives, I’ll immediately test the 48/24/48A-written discs with Plextools Pro for reliability. If they fail, I’ll use the drive as a last resort backup…

If you read this far, maybe you can give me your opinion: any ideas if the lens is severely damaged? Is it sending the laser all over the disc, making the black, nonreflective disc tray completely obsolete and burning semi-coasters?


For now I would not use the drive for data backup any more. Just see what the Q-Check tells you.

Can you recommend some software to test the drive write quality, until the new drive arrives? I have never made such test, but I heard about Plextools Pro and KProbe for now.


I made observation that KProbe scans are very, very inacurate. Think you have to wait for the new drive.

You can buy a Premium to test the writing quality,it is exacter than any other drivers.

Thanks for the ideas.

By the way, AKINA, I wanted to save the old drive, not buy a new one right away :slight_smile:

Anyway, I got something better than the Premium: i just received the Plextor 712A DVDRW (thanks go to my boss)!
And it’s black and elegant (hey, it’s my new toy, it was time to upgrade to DVDs anyway) :slight_smile:

Will make some tests when time permits (I have some close deadlines right now). I understood it also has the testing features that the Premium has.

Hopefully, I won’t have to throw my old Plexwriter away…

On the other hand, can anyone tell me if Verbatim or TDK DVDs are better? I was a TDK CD fan, but then I got some which vibrated really badly, so I turned to Verbatim and used them ever since.
Don’t know about the DVDs, though…



Plextools with the Plextor 712A DVDRW drive does not do Q-Check PI/PO tests on CDs, only on DVDs. So it’s useless in verifying how well my old CDRW drive writes.

I was hoping for the PI/PO tests, because I read and understood some basic rules about them in the CDRFreaks review of the 712A writer.

Well, I guess I’ll use the C1/C2 tests, then learn how to evaluate them :slight_smile:

ANIKA, you were right - the only drive to be able to fully test a written cd’s quality is the Premium. However, I won’t exchange the new 712A DVDRW for a Premium, hope you understand me :slight_smile:

Hi Constantinus

No drive will do PI/PO error tests on CD-RW, this is for DVD only and only the PX-712A can do PI/PO error tests on DVD


@Constantanius: C1/C2 is for CDs. PI/PO is for DVDs.

And this will come in useful too:

Interpreting PI/PO error scans (DVD media)
Interpreting C1/C2 error scans (CD media)

Thanks G@M3FR3@K it’s very interesting! :bow:

Thanks, I’m loading the C1/C2 thread right now.

But first: I did a C1/C2 test with Plextools Pro 2.15 and the Plextor 712A DVDRW, on a rewritable Verbatim 10x CD. Haven’t tested with CD-ROM yet. Will do later.

What I did is as follows:

  • took an old CDRW that was written with the old drive, before the accident;
  • using the new drive, ran Plextools Pro C1/C2 check on the CD;
  • saved the graph;
  • using the new drive, I created an image of the CD, on the HDD;
  • using the new drive, erased the CD;
  • using the old drive, re-wrote the image to the CD;
  • using the new drive, ran Plextools Pro C1/C2 check on the CD;
  • saved the graph;
  • compared the two graphs.

Surprise: the new graph had lower peaks and (it seemed) the average was lower, as well.
I did not write down numbers, because I was expecting huge peaks, some quite visible differences between after’n’before, but not this.

If the drive in undamaged, I think the lower C1/C2 in the new write comes from the fact that the old write was written a while ago, and maybe it started to fade (I read rewritables tend to do that). Maybe the new write “refreshed” the disc, although I didn’t do a full reformat before writing. Maybe.

Thus, my hopes are high that the drive is not damaged. But, who knows, maybe it won’t be able to focus on CDRs, or something, it will write ok only on CDRW? Seems improbable.

Friend of mine had 4824A that did produced (Nero verification) errors on 24x CD-RW. The C1/C2 greaph looked qutie normal though. You shouldn’t rely on the drive to produce any useful burns any more!