"Mike Stucka"
wrote in message ...

James Sweet wrote:
What's the brand and model? Is this by chance a GE/RCA/Proscan?
If so then resolder the tuner shield grounds. Otherwise, look elsewhere
for cracked solder joints. Don't use it again until you fix it, further
damage is likely.

Please disregard the earlier message. I'll try a fix this weekend,
but it sure looks like you nailed it right off the cuff. As weird as
the symptoms are, this seems to match up perfectly with the
tuner shield ground failu
http://www.audiokarma.org/forums/showthread.php?t=78503


I'd like to start a side discussion on this.

Many years ago I briefly attended RCA Institutes in New York. I had a mild
argument with one of the instructors, taking the position that theory was
the most-important thing, that a good tech should have a sound understanding
of electronics. (RCA taught many subjects at a college level.) He, on the
other hand, averred that technicians should learn and work by rote.

40 years have not changed my views on this matter. But it is true that any
good technician knows hundreds of things he learned only by practical,
real-world, day-to-day experience, stuff that didn't come out of a book. One
of the reasons I like reading the threads in this group is adding to my
repository of such information.

I'm coming to a point, so hang on.

When I see the OP's symptoms -- which pointed to vertical sync problems --
resolved by fixing a cracked solder joint on the tuner shield -- I can only
wonder in amazement. How did anyone ever figure that out? Or was it a case
of a part-by-part visual examination of the entire set when nothing else
worked? Broadly speaking... how does anyone go about "rationally" analyzing
such problems?

When I was a kid, I read "Mac's Service Shop" and similar short stories in
Popular Electronics and Popular Science. Back then, intractable problems
were called "tough dogs". Given the greatly increased complexity of modern
electronics, they're more like "rabid wolves".

PS: One of my high school friends was very much against "book learning". We
were trying to repair a TV in electronics shop at around the time I was
working through Milton S. Kiver's "Television Simplified". I had just read
the chapter on sync, and had a good idea which component was defective. My
friend was rather surprised when that component turned out to be the bad
one.

The advantage of "book learning" is that it gives one a framework on which
to hang all his practical experiences.