# Identifying PM part in cd/dvd-rom



## lanfear (Apr 30, 2013)

Hi guys

I have been scrapping some cd, dvd rom's and some floppy drives. And I have found some plated parts. Do anyone have experience with these parts?


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## Captobvious (Apr 30, 2013)

Best guess, brass


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## gubni (Apr 30, 2013)

I don't think they use brass to plate a base metal do they? An easy test might be to do a scratch test to see if it's plated? Just a guess from a newb.


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## lanfear (Apr 30, 2013)

I thought of brass. But thats not it. Gold has it's own shine in sun light. The tree small objects is from the optical device, and they have gold leads. The dotted coin I think is from a zip drive, but I can't remember exactly.. To bad, cau's it's really nice, and i'm pretty sure it's gold plated.


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## ilikesilver (Apr 30, 2013)

lanfear said:


> Hi guys
> 
> I have been scrapping some cd, dvd rom's and some floppy drives. And I have found some plated parts. Do anyone have experience with these parts?



brass will have a redish tint in the sunlight


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## Geo (Apr 30, 2013)

dont waste your time or energy looking for gold on every piece of yellow metal. think about it, why would they put an expensive metal like gold on an inexpensive part that doesnt need corrosion protection or electrical contact. look for precious metal where they are known to be. if you look on youtube, you will be collecting hard drive covers that are 6K gold.


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## g_axelsson (May 3, 2013)

lanfear said:


> Hi guys
> 
> I have been scrapping some cd, dvd rom's and some floppy drives. And I have found some plated parts. Do anyone have experience with these parts?


From the top down...
1. Laser diode, gold plated house, probably gold flash (really thin)
2. 3. Looks like optical mounts but a bit hard to see on the picture. Is there lenses and other glass components inside the cylinder? Could be gold plated but most probably brass.
4. Looks like a central part of the rotating disk. Most probably brass.

Put a drop of nitric on each object. then you'll see if it's gold plated and how thick or thin. Any gold will come off as thin foils and is easily seen in the acid.

Göran


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## Smack (May 3, 2013)

Top one is gold plate like Goran said, the rest is brass.


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## lanfear (May 13, 2013)

Thanks for the reply guys. The 3 top most are all laser housings. And I though they were gold. But I guess I would need allot to get any yields. The last one is as g_axelsson claims, from a rotating disc.
I will need to get some nitric so I can start to test the stuff myself. :roll:


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## rickbb (May 16, 2013)

They really only put gold on electrical parts either as a preventive to corrosion or for high conductivity, as in the CPU. 
Moving parts are usually a type of brass that has been infused with oil for lubrication.


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## Sodbuster (May 25, 2013)

lanfear said:


> Thanks for the reply guys. The 3 top most are all laser housings. And I though they were gold. But I guess I would need allot to get any yields. The last one is as g_axelsson claims, from a rotating disc.
> I will need to get some nitric so I can start to test the stuff myself. :roll:



I used to think the same thing about #2 and #3, but then I discovered that (If it is in fact a laser housing) you can finish breaking it down and you will have three #1's. 
It will be glued in or pressed into that brass barrel. look close to see witch way to punch it on out.

Know that a percent of the ones pressed into the barrel like that will not be gold plated.

Sense you come this far.
For the ones that are gold plated, I crack that stainless cap off to expose the gold plated base and the solid gold bonding wires ( if they didn't get scratched off when you took the cap off ) on the inside, before going to my stripping cell. 
Sometimes the leads wont strip with the rest so I fold, or twist the leads to make contact with the base if need be.

Some will have better plating than others, but very sparse in any case. You will need a pickup truck load of diodes to make you a gold button the size of a BB, but heck it's a hobby right? 

Ray


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## solar_plasma (Oct 7, 2013)

Laser diode from a cheap laser pointer. Looks like a lot gold plating, gold bondwires and some interesting solder.


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