Surprizingly, the PC board on my 14" RCA portable is in pertty good shape, despite the heat this thing produces.
The chroma board on my CTC-16 had foil problems, wnich I was able to fix.
The Sylvania portable I have has a PC board that drove me nuts during the restoration. I resoldered more joints than I care to count, and the set is still not perfect.
I have noticed that most manufacturers that used PC boards from that era had problems of one kind or another, with RCA being notorious.
I did put more details on the PC board issues on the two BW sets on my website.
www.geocities.com/evilfurnaceman