Another question for those who were "there"...

[zeno]

Thinking back ( Zenith - Admiral shop) The flat chassis had few problems.
Hybrids, 14 & 16" sets were more trouble. The upright chassis
(19EC45 etc) had lots of problems at first. Strange because except the vert it was mostly a re arranged flat chassis. Lots of vert boards, H outs,dampers, 24 V regs, & tuners.
System 3 was almost all 9-160 failures followed by
9-155's then selectors. after a while they got the bugs out & they
were more reliable.
9-181 sets were also troublesome at first but
shortly became very reliable. I will end it there. After that there we
too many chassis changes.

Admiral tube sets were dogs, I always hated selling them. The
solid state 13, 17& 19" sets were never any good. Constant vert
and pass transistors (2 of them) failures. Near admirals end they switched
to a non modular set that was very good. That continued for a few
years under AOC then the quality fell to very poor.
SS Consoles were super reliable and we saw few come back. As good
as any but they needed a CRT with more snap, the pix was not
up to date.

73 Zeno