# Different platings on fingers



## jamthe3 (Feb 5, 2009)

Good evening all! I was wondering if there are other kinds of plated fingers other than gold. When removing some cards off of circuit boards I've noticed some of the fingers are not gold in color but rather shiny silver. I'm assuming they are plated w/ a different metal and figured someone else would probably already have the information as to what possible metals it might be.

Thanks in advance,
John


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## lazersteve (Feb 6, 2009)

John,

Typically, silver colored fingers are only solder coated copper traces.

Some of the PCI card slot fingers are very lightly gold plated and have a semi-silver appearance.

Steve


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## jamthe3 (Feb 6, 2009)

Thanks Steve. Am I correct in assuming (w/ the possible exception of the PCI ones) that these are better of economically to leave be?

John


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## slowerbear (Feb 10, 2009)

Actually, Hewlett Packard utillized a wide variety of plating materials for circuit boards and associated fingers. It was very common in the 50's and 60's to use both platinum and palladium in high performance oscilator circuits. By accident, I discovered the difference between silver and palladium plating in a large junk heap of discarded circuits. In essence, the dull/oxidized boards were plated with silver. The boards that remained bright and shiny were plated with palladium. Testing validated the hypothesis. These boards still show up occasionally in lot's of discarded HP test equipment. Trust me--Every milligram is recovered!


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## goldsilverpro (Feb 15, 2009)

In the 60s, Zerox used rhodium plated fingers on some boards.


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## Platdigger (Feb 15, 2009)

Not sure if it is true, but long ago I heard that some key boards made in the early 80s had some rhodium plating under the keys. (contacts)
Randy


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## Charlena (Feb 16, 2009)

Platdigger said:


> Not sure if it is true, but long ago I heard that some key boards made in the early 80s had some rhodium plating under the keys. (contacts)
> Randy



That's why they were selling for 500 bucks all beaten up broken on ebay and 1000 if they were like new!
Wow Ive been looking for the reason that phenomenon had taken place on the market! 
Old IMB Cl-icky keyboards...wow


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## SilverFox (Feb 16, 2009)

.....

At one point my dive shop had like 7 of those, to think the worthless 80/86 generation keyboard was nothing but a rhodium mine. At the time, it was just worthless junk to me.


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## steveonmars (Apr 17, 2009)

Does anyone have a photo or link to see what these keyboards looks like?

I just took about a dozen old IBM keyboards apart that have a steel plate that you have to use pliers or a screwdriver to pop the keys off. Then there's 3 little gold colored plates under the keys that you pull off with pliers. I've just been tossing these in a bucket with other unknown stuff to go through later. 

I still have 6 or 8 that I haven't popped the keys off yet, but I did pull the plastic covers off and cut the cords. I can screw the covers back on and sell them without the cords if there're going for that much!

Steve


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## steveonmars (Apr 17, 2009)

I just went and looked and I already through the plastic cases in with the recycling and they're gone.  

Here's a couple similar keyboards on ebay that's looks very close to mine, slightly different.

Item number: 380117498908
Item number: 200256030747

There's more but they aren't selling for much or don't even have bids.

I have 10 of these still sitting outside, steel plate with keys only.

Steve


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## steveonmars (Apr 17, 2009)

If these are the ones with the rhodium, is this something I can refine? If not is there somewhere to sell the rhodium plated parts only, a refiner maybe?

Thanks, I'll shut up now and give you guys a chance to actually read my posts instead of dominating the thread.

Steve


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