CD-R/W drive spindle clamp magnet catastrophic failure.

Well it is pretty catastrophic to me ;-)

I have an ASUS CRW-4012a that has been working great for years now, and has recently started to have "issues" seeing a disk in the drive and it started making noise, (the kind of sound that makes you think a plastic disk is slipping and there is friction noise from it).

Since it is no longer covered by the manufacturer warranty, I decided to take it apart and see what was going on.

At first I couldn't figure out what could be wrong as all the motors seem to operate normally, and the gears are intact. There was a bit of dust, but I cleaned that out and re-lubed the stepper gear as well as the rails the head travels on. I then started to focus on the clamping mechanism. Typically what I have seen in the past is on the spindle there is a magnet of some type attached (screwed or glued), in this units case, there was what I identified as a magnet, but parts of it were shiny (hardly any) and other parts were rather black, like as if it had some funky gunk on it. I went to wipe it off and discovered the funky stuff was the magnet.

It would appear that this (and I guess many now) magnet is made by taking a ferrite magnetic powder and encasing it with a layer what looks like chrome. The problem appears to be that the outer shell wore away somehow or was damaged at some point (more likely they knew it would die after a couple years and people would just buy entire new drives) and then we only had loose magnetic particles trying to pull down the upper platter of the clamp and spin it. That explains the noise and it's failure to spin up properly (especially at 40x).

After cleaning some of the material that had been thrown onto the few metallic parts in the unit I was able to verify the drive is still functional, but I need to replace the clamping magnet.

Does anyone have any idea where I might find a non powdered replacement or what I should look for?

Reply to
dphilli8
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You probably don't want to hear this, but my advice- bin the drive and buy a new one. They're not exactly one of the more expensive PC parts, and if it's years old there'll likely be other parts near the end of their life. You can get a dual layer DVD writer now for far less than a CDRW of that vintage would have cost. You might find a similar magnet in a scrap drive, but is it really worth the bother?

Dave

Reply to
Dave D

My advice is to look for a dead drive and salvage the clamp from that, it's not gonna be worth buying a new part.

Reply to
James Sweet

Hello There....by your description of the magnet, it sounds like a Neodymium or "rare earth" magnet. These are usually coated in "chrome" and if you chip the coating away the underlying magnet has a "powdered" look to it. These have now become VERY common and you should be able to find a suitable replacement. Do a search for "rare earth magnet" on the net and I'm sure you'll find some place in your city that carries them. I live in Canada and a place called "Lee Valley Tools" has them in various sizes and shapes for a dollar or two each. The smallest they carry is a mere 1/4" in Diameter by 1/8" thick !

Good luck......Dean.

Reply to
Dean B.

The magnets are made that way because they can't get the same strength out a rigid material in that size for the same price. You probably won't find a harder replacement that will fit.

I doubt they made them fail > It would appear that this (and I guess many now) magnet is made by

...

Reply to
Mike Berger

I'd rather not replace it with a DVD writer as I already have one. I like to have a decent 40x CD-ROM for games and burning CD media saves wear and tear on the DVD drive. I also enjoy troubleshooting/fixing things, so I thought it was worth asking.

Reply to
dphilli8

Me too! However, I don't spend more than about ten minutes on CD Roms these days though, I quickly discovered most failures are not worth the time and effort.

Always worth asking. Good luck with the repair.

Dave

Reply to
Dave D

The strange thing is this is almost my youngest drive in the house. All my significantly older/slower ones still truck along, and my other 40x units (different manufacturer) seem to be fine. I have not mistreated it so I can only assume the drive/loading mechanism must have somehow been causing damage to it.

As for intentional design flaws, that is just my cynical side saying the worst about corporate thinking. I know a lot of gamers and they would just toss a drive (or other component) that quit working and buy another, even if it was easily repairable. Back when that stolen electrolyte formula was in heavy use I managed to get quite a few motherboards to fix due to this mindset. Speaking of intentionally bad design, those gateway lunch boxes that have only a sleeve fan in the power supply are quite evil. I just finished repairing 6 for a preschool, new caps all around and real bearing fans put in the power supplies. IMO there is no way that bad of a design was accidental.

Reply to
dphilli8

Thanks you (all of you) for your replys. When I was starting to look I ran across a TDK PDF file talking about the product the magnetics division made and things they are used for. From what I could tell they have 3 types they make for drive clamping in the ferrite dry anisotropic type (formula is SrO6Fe2O3) parts FB5D, FB3N and FB3G. Shape according to them was called DH (I'm guessing for doughnut hole).

I'm going to cannibalize my 1 dead drive (a DVD/CD-R combo) that overheated and see what I can do, and then check on what I can find based on what you suggested.

Reply to
dphilli8

Don't know about the clamping magnets but simular magnets in pager motors and other motors indoor flyers use have had that same issue. They are formed rare earths with chrome overcoating and they all fail in the same manner. The crome just flakes off and jams the motors. It must be a manufacturing problem. If you posted pics and dimenslions we all have lots of junked CD-ROM drives that we could send you a simular part. Richard

Reply to
spudnuty

Aren't most DVD writers faster than that? My CD-RW drive is 52X and was under 50 bucks several years ago. By all means, try to fix what you have, but I really wouldn't worry about wear and tear on a DVD writer, they're well under 100 bucks now and will likely be obsolete long before it wears out.

Reply to
James Sweet

Maybe now, but a year-and-a-half ago, one of the selling points of the Lite-On drive I bought was that, unlike other brands, similar (to CD-RW) CD performance was possible.

Tom

Reply to
Tom MacIntyre

On 27 Sep 2005 10:00:43 -0700, snipped-for-privacy@columbus.rr.com put finger to keyboard and composed:

I'd be wary of replacing just the magnet. Balancing could be a big issue.

-- Franc Zabkar

Please remove one 'i' from my address when replying by email.

Reply to
Franc Zabkar

I'm thinking "replace the whole thing". I also just repaired a Daewoo DVD player that had a balance problem in the clamping assembly. The assembly was not completely snapped together. It had either come unsnapped or was never snapped completely in assembly. It was so bad that you could feel the vibration when the unit spun up. The client said it just wouldn't read some DVDs Richard

Reply to
spudnuty

Reply to
Mike Berger

I would look for a scrap CD-ROM drive and use the entire clamping assembly if you can. Andy Cuffe

snipped-for-privacy@psu.edu

Reply to
Andy Cuffe

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