So I'm tearing down a pile of hard drives. Old and new. and I'm looking at the plastic coated ribbon cable that goes from the head armature to the controller board. it's encased in what might be a copper colored mylar. and some of the traces are very tiny. was wondering if anyone has tested those for any PMs? Sure, a bunch have little gold plated pads for grounding, but I'm wondering if there may be silver in them. Since the traces are so small and critical I was hoping they used more than just copper. Anyone test any of these?