"Scrim" wrote in message
...
I'm experienced with electronics but don't know much about TV's. Can
anyone help me identify this problem?

Panasonic TX-W28R4
Recently: After switching on from cold every now and then the picture
starts to shrink in the vertical direction. I bang the top a few times
over a space of 15 minutes each time this happens after which it's warmed
up and works fine. Sometimes the picture shrinks to the bottom inch or two
of the screen and is scrambled. Occasionally the screen goes blank and the
TV shortly afterwards shuts itself off.

I lived with that but now the problem is worse. A few seconds after
switching on and nothing appearing to happen, there is a flash on the
screen of light collapsing towards the centre as the TV shuts off. I can't
use it at all any more.

I vacuumed the circuit boards free of dust and this gave me two more days.
I just tried pulling/reinserted all the connectors but that hasn't helped.

Any ideas gratefully received.

Scrim

Bad joints on the field output chip. Very common on Pans of a few years old.
Fix it now before the IC fails from all the arcing and flashing about on its
pins, or the board starts to burn up around the bad joint. Even if you can't
actually see anything that looks like a bad joint on any of the pins, reflow
them with some new solder anyway.

Arfa