Quote Originally Posted by brandon View Post
^^^ thats copper
Its 'tinned' brass, I think. I do see yellow brass heatsinks occasionally, mostly over electric motor driver chips.



Those heatsinks above ^ often have a couple of iron wires pressed into them to solder them to the board.

The motor driver chip brass heatsinks are normally soldered to the board & come from 70's Tv's. They may also protect everything else on the board from the EMF (electromagnetic field/force) the chips may make as they cover the whole chip.
A interesting distraction when scrapping.