Anything left on this board worth anything?

[AndrewSuperD]

Seems like I find conflicting answers on PMs in through-hole lead-type resistors. SMD, yes, but what about these pictured? I think I got most gold off this board. There is more in the white plug and the red component’s lead legs… anything in any of the rest of this? Came from a Kentrox CSU. Thanks for the look!

 

[Ohiogoldfever]

Visible gold on these component. Possible gold in that small IC. Gold bonding wire in those Leds.

 

[AndrewSuperD]

Visible gold on these component. Possible gold in that small IC. Gold bonding wire in those Leds.

Great! Thank you! I forgot about LEDs

 

[Christian333]

Seems like I find conflicting answers on PMs in through-hole lead-type resistors. SMD, yes, but what about these pictured? I think I got most gold off this board. There is more in the white plug and the red component’s lead legs… anything in any of the rest of this? Came from a Kentrox CSU. Thanks for the look!

The axial mount resistors can have gold plated end caps, mostly older vintage type. Here's two examples, both tested positive for gold as evidenced by nitric acid leach with no effect on the gold foil. Then AR with stannous to confirm.

Janie

 

[Alondro]

The long blue resistor arrays at the top left in the last picture can have silver and palladium. The switches on the lower right usually have silver-plated contacts, but occasionally gold.

 

[eaglekeeper]

After you remove the legs there's usually a non-magnetic MLCC in the yellow one that's circled.

 

[Rreyes097]

Great! Thank you! I forgot about LEDs

Do all LEDs contain silver? Because I've always passed up the leds. But when I read about them containing silver I still didn't know which ones contained silver or not.

 

[eaglekeeper]

I don't know if there's a way to determine which ones contain silver or not. Even if there was a list, I've never seen a PN# marking on standard LED's to compare to that list...Idk.

999 Dusan on YouTube has a video processing mixed LED's...... Owltech also has a video with LED's...... Like and Subscribe to their cannels.

 

[AndrewSuperD]

The axial mount resistors can have gold plated end caps, mostly older vintage type. Here's two examples, both tested positive for gold as evidenced by nitric acid leach with no effect on the gold foil. Then AR with stannous to confirm.

Janie

Thank you very much. I’ve pulled the larger resistors apart and they didn’t have any end caps at all! I pulled the one tan colored larger resistor apart and found the resistive material was wrapped in copper wiring.

 

[AndrewSuperD]

The long blue resistor arrays at the top left in the last picture can have silver and palladium. The switches on the lower right usually have silver-plated contacts, but occasionally gold.

Thanks so much!!

 

[AndrewSuperD]

After you remove the legs there's usually a non-magnetic MLCC in the yellow one that's circled.

View attachment 53340View attachment 53341

Great eye!! Thank you.

 

[AndrewSuperD]

I don't know if there's a way to determine which ones contain silver or not. Even if there was a list, I've never seen a PN# marking on standard LED's to compare to that list...Idk.

999 Dusan on YouTube has a video processing mixed LED's...... Owltech also has a video with LED's...... Like and Subscribe to their cannels.

Will watch these after I watch “A Christmas Story” for the 500th time!! . Thanks a bunch!

 

[eaglekeeper]

Will watch these after I watch “A Christmas Story” for the 500th time!! . Thanks a bunch!

Classic...

 

[BlackLabel]

The two switches beside the LEDs seem to have gold plated wires. The contacts inside also could be gold plated.

 

[BlackLabel]

As OwlTech launched his video about the LEDs, I had a little conversation with him.

His LEDs were older Soviet types. They had gold plated pins. His gold yield was surprisingly high, but it was a lot of work (2 days) and he used a gallon of nitric acid.

His conclusion:
"NEVER AGAIN! Even if I get them for free..."

 

[Alondro]

As OwlTech launched his video about the LEDs, I had a little conversation with him.

His LEDs were older Soviet types. They had gold plated pins. His gold yield was surprisingly high, but it was a lot of work (2 days) and he used a gallon of nitric acid.

His conclusion:
"NEVER AGAIN! Even if I get them for free..."

That's why the HCl-CuCl2 method is so useful, though slow-working. Eats up base metals cheaply, and can dissolve quite a lot of metal.

I have a jar of LEDs. They'll get the plastic parts burned off, then into the leach they go! I can see the little bond wires inside them. But also, there are other interesting metals in some of them, such as rhenium and, rarely, rhodium plating in the little 'cups'.

 

[BShan]

Connectors at the top (three black connectors, each with 2 holes for some kind of barrel with multiple rings) have metal contacts sintered onto the leads. That little bit of metal might be a silver alloy. I say this mainly because of their construction; my test came back negative, but after checking with some sterling, I think my schwerters is bad.

 

[FrugalRefiner]

...after checking with some sterling, I think my schwerters is bad.

How old is your Schwerters? I've had it go bad after a year.

What color is it? It starts as a nice orange, but gets darker with age, and ends up a dark green.

What reaction do you get when you use it? Color on the metal, color on a paper towel when you wipe it off and whether that fades or changes color, any color change on the metal where you tested.

If it didn't give a positive test on known sterling, it's probably dead. Dispose of it properly. Chromium ions are very hazardous.

Dave

 

[eaglekeeper]

What color is it? It starts as a nice orange, but gets darker with age, and ends up a dark green.

Yea, mine turned dark blue'ish. I can only use it to check if silver is present by adding a couple grains of salt, but that's about it. Not good for checking sterling/coin silver.

Sreetips has a video on how to make Schwerters, but I'm very Leary about buying chemicals on line. I don't know if buying dichromats will put me on a list somewhere.