They were a very good set. The only common problem was on older
ones the modules & main PCB was printed on both sides. The
connection between the sides would get cold & you get all sorts of
intermitants. Later they hard wired them & soon redesigned them
with one sided PCB's. They were the first to learn NOT to use
double sides. Everyone that did it regretted it
73 Zeno
LFOD !