C'mon guys, he said he had vertical collapse on a Panasonic 27G22 that was
affected by tapping on the set. He just needs to resolder the output IC and
the related parts. If that doesn't do it then he should take it in, but
these repairs are usually very routine.

Leonard

"Art" wrote in message
...
I tend to agree with Jerry G, having not seen the new chassis since
tube.transistor mix will definitely cause a severe limitation to your
ability to rectify this set yourself. Best to have an authorized servicer
repair it for you. However: if you do want to do this, get yourself the
appropriate service manual from Panasonic and have at it. Going in there
blind is only going to frustrate you with the inability to do this.
"Lance Dyer" wrote in message
...
the vertical ic is usually labeled as IC 4-- on the board and should be
a
LA 7636 or similar label on the ic itself which is mounted on a heat
sink
vertical yoke wires should be close by

"Charlie Bress" wrote in message
...
With no board layout or schematic how can I id which device it is?
Is it on a heat sink? Typical pn's? I have the soldering iron, I have
the
solder and the ability. What I need is a way of telling which device it
is.

Charlie

"Lance Dyer" wrote in message
...
start with resoldering the vertical output IC It is common for these
connections to crack and give that problem


"Charlie Bress" wrote in message
...
The model is a 27G22V, the chassis is APEDP280.
This set has had an intermittent vertical collapse/instability
problem
for
some time.
This only shows up cold. After 5 minutes it is stable and stays that
way
until it is cold again.
It has been pretty consistent in always showing the problem.
A slight bump on the case will generally eliminate the problem for
the
session.

I finally got a neighbor to help pull it out of the entertainment
center.

I have been looking for a bad solder joint or other bit of
flakiness.
Nothing shows up visually. I have inspected most of the solder side
with
a
magnifier. I have jiggled the leads going to the yoke. I have used
an
old
aligning tool to push, poke, prod and otherwise try to replicate the
problem.
Of course, everything works without a hitch

Since I have not had the need to get into the innards of a set since
the
days of hybrids, I don't recognize circuits by their layout and
component
mix. What is being used for the vertical amp/output device? I
don't
have
a
cold spray and the heat gun seems like it is going the wrong way

Suggestions are solicited on what might be next. I hate to just
button
it
up
and put it back without resolution.

Charlie

The first TV I ever worked on was a 7" Dumont that had a brute force
HV
supply and electrostatic deflection.
.