When good CD-Rs go bad

For those who have never actually experienced the results of a CD-R exploding, or thought such things were folklore, I thought I'd share my experience.

Yesterday I put a cd-r in one of my drives, a disc I had used just a week ago, but to my surprise it wasn't being read. I reinserted the disc a couple more times, still no good. I took it to another PC and tried it, still was not being read. I took the disc out and examined it. There was a very tiny hair-line fracture that went from the inner hole straight out for about maybe an inch an a half. Hmmm! Well I wanted to try and pull some of the data off the cd so I decided to try to use one of my utility programs designed to recovery bad cds. I put the cd in and fired up the program. It chugged away for maybe 3 or 4 minutes. All of a sudden there was a loud bang, as if (literally) a firecracker had gone off. I quickly opened the drive door and found the following on the drive tray (excuse the fuzzy image, but...):
http://www.imagestation.com/picture/...2/f82c2837.jpg

This was the ONLY thing on the tray.:eek:

I took the drive out and opened it up to inspect it and clean it out. Inside the drive I found two other pieces about half the size of the above. plus maybe what amounted to a teaspoon or so of crystal size pieces. Any thing else that once was my cd-r seemed to simply be turned to dust or disintegrated. Fortunately after carefull cleaning and testing the drive itself seems to have survived (guess Liteon made a decent drive). I consider that quite lucky. Clearly there was quite an eruption inside. More than enough to damage something, especially the delicate laser lens. Heck, I can see why the companies talked about reinforcing the drive doors.

I've worked with computers a long time, and used more cds than I care to think about. But this was the first time I had actually experienced the "exploding cd". Sure, I've heard about and knew it could happen but... The cd in question was not otherwise damaged in any way before use. It had been well taken care of. And it was not all that old (like a year I guess). How the hairline crack ocurred I can't say. But the moral of this story I guess is simply that it pays to examine your discs when you use them, and take care of them when not in use. And if you ever notice they are structurally compromised in any way its likely they are just a couple good spins away from having the 4th of July take place in your cd drive.:eek: And if you are lucky (like I was) you will only loose a cd and not your drive along with it.

WOW!!! I don't wanna read about another one of these happenings. Glad your drive was not ruined and hope the contents on the demised CD are replaceable.
Thanks for sharing this experience.

At the RPMs those things are spinning the centrifugal force at time of explosion would be quite great.

Imagine if pieces came firing out the front of the drive like ninja stars and you leg or something just happend to be be right there.

As it is, I have a 3cm scar on the back of my hand from where I was bending doen to pick up a dropped CD and the back of my hand came in contact with the corner of the open CD tray - scraaaaatccch

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But the moral of this story I guess is simply that it pays to examine your discs when you use them, and take care of them when not in use.

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Ohhhhhh....this is SO not me on every level! I'm forever sorting through piles, that I swear, I'm going to sort neatly.

You've inspired me. I'll aim to do better. :o







Ok....... a tiny piece of me did go, "Wow! How cool is that?!" :D :p

My eldest son's first cd-rom was fo his 2nd birthday.

Within a week he had cracked it by chewing on it.

Still worked although I promptly made a cop of it to use instead.

That's kinda scary since we all back up our data to CD now. I thought those things were supposed to last 50 years. :(

http://www.powerlabs.org/cdexplode.htm - includes a lin kto some video footage of this guys cazy experiments.

http://www.paintbug.com/cdexplode/


And what happens if you put them in the microwave

http://www.prairienet.org/~tatwell/cd_burning.html

http://hamjudo.com/notes/cdrom.html


And finally other crazy microwave shennanigans

http://margo.student.utwente.nl/el/microwave/

Thank heavens you or your drive weren't hurt when this happened Doc!
An experience I had was with a CD cabinet I bought. Simple plastic case with removeable CD holders inside. These 'holders' snap into slots on the bottom of the case. Looks like a good way to store disks,except for 'one' thing I found. The center of the holder has raised plastic nubs(best explanation I can come up with),that your supposed to press through the center hole of the CD. I found it was quite hard to get a disk to snap onto some of them without rolling the disk around and pressing fairly hard to get it to snap on.
Then I saw the Guys on techTV trying to destroy CD's by mounting them on a high speed turntable. And 'boy' did it 'work'! They exploded all over the place. They explained this would probably not happen in ordinary use,but to watch out just the same.
After seeing this,it dawned on me what may happen using the snap-on holders in the cases I bought! :eek: Needless to say, I still use the cases,but I 'do not' mount the disks on the holders.:rolleyes:

I tell ya, after this experience I think there should be printing on all cd-r boxes that says "Also suitable for use as a fragmentation grenade."

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I thought those things were supposed to last 50 years

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My guess is that the pieces I recovered and threw out will in fact probably last 50 years in the landfill.:eek: :D

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Ok....... a tiny piece of me did go, "Wow! How cool is that?!"

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Ya crack me up Daizy! Aside from potentially loosing some data, nearly ruining my drive and soiling myself from the shock of the sound, I guess ya could say it was kind of cool.:D

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Thank heavens you or your drive weren't hurt

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I tell ya Ridge, I am amazed the drive survived. And as for me: the only harm done is a bruised ego from being so stupid as to tempt fate and try too hard to salvage the cd's data.


An update on this all though... I did some checking of various burned cds I had. Most were fine. BUT, I found that I had 12 others still around (and in use) that were the same brand (from the same batch) that the one that exploded was. Ten out of the twelve had the beginnings of a similar hair-line fracture from the spindle hole out. I know these fractures were not there from the start. So I can only conclude that there was some weakness in their construction such that over time the presssure from the center hub of the jewel case (they were all in cases) caused them to start cracking (just sitting in the cases). Only cds from this one particular batch seemed to have the problem. Fortunately these failing cds (10) were not too far gone yet and I was able to read and copy them to new blanks and salvage what was on them. Glad I caught it in time.:)

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Originally posted by DrMDJ
I tell ya, after this experience I think there should be printing on all cd-r boxes that says "Also suitable for use as a fragmentation grenade."

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http://www.paintbug.com/cdexplode/images/varning.gif

My questions is, what would make a cd explode? It wouldn't happen for just no reason. What are the chances that the laser went nuts and burnt it to bits? What other explanation do you have for it? IMO, Spinning alone doesn't seem like a reason for it to explode like that. As with any laser products, there is some danger to using them. I'm puzzled.

You obviously didn't read the second link I posted.

It had all the information you could require to answer your doubts.

Like the fact that a CD at 52x is doing 27,000rpm and at 30,000 rpm the periphery of the disc would have force of > 1500 G subjected on it.

..and from the first link

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The Dremel was switched on and the rotational velocity was gradually increased to its maximum, at which point the CD hummed and whined in a very menacing manner. Mildly disappointed that it had not exploded, I realized that it wanted out; a quick jerk at the tool and the CD slid out of the holder and contacted the carpet whilst spinning at ungodly speeds. It peeled out a bit in front of me and proceeded to make its way to the door at a very high speed. On contacting the closed door, the CD did a most unexpected thing: it first bounced back a few inches, and then, when it hit the door again, it jumped straight up the door and struck the ceiling, exploding into thousands of fragments which rained down on the entire room. This first experiment was unfortunately not videoed, but it served to get everyone in the room to put glasses on and cower away behind pieces of furniture, whilst people in the hall corridor quickly made their way to my door to ask what was going on. Now, with an audience, the camera was taken out and the real experimentation began...
A standard compact disk has a diameter of 12cm. If this disk is to spin at 35000RPM, the peripheral velocity at the edges of the disk (.377m circumference x 583.3 turns per second) will near 220m/s, or 722fps, or 792km/h or 492miles per hour. That is one fast CD-Rom!

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I'm not going to try this crazy $h!t at home but you can if you still don't believe 'spinning alone' will do it.

That was a tad too much reading for me as I was on my way out. The summary that you wrote sufficed.

From what I read recently, I think the prime suspect here is jewel cases - some of them seem to exert a lot of pressure on thge centre hole. I've stopped using jewel cases, primarily on the grounds of the space they take up, but it looks as though I've got another reason for being glad that I did so. These days I use plastic sleeves or carry cases.

Thanks for the warning Doc, my optical drives are at excactly eye level, and I've heard of CD's exploding right through the front tray, so I'm going to inspect CD's a lot more carefully in future.