Harvey White wrote on 1/5/2021 8:55 PM:
Printed circuit boards are generally made with one of two materials (there are others), either a paper epoxy (FR-3) or a fiberglass epoxy (FR-4). There are others, but these are most common.Hello--
Older imported electronics used a phenolic-based laminate-- typically medium to dark brown
and liable to losing its traces when the repairer applied too much heat. Oh, and when overheated
it smelled like warm horse s*it.