Toshiba 36 inch tube vertical shrink problems...

[[email protected]]

I have a 36" tube Toshiba - model CF36G40 (Jan 97). The screen will
sometimes shrink vertically with large black bands top and bottom.
Sometimes it will actually expand such that the top and bottom are cut
off. It does not seem to get worse or improve as the set warms up, but
it is more frequent when watching a letterbox program.

I replaced capacitors C305, C308 and C320. Also, I reflowed some
suspect looking solder joints while I was in there. This did not help
at all. Same problem exists.

Any suggestions? I've read that C301 causes other problems. Any
particular caps that I should replace or chips to reflow solder on
maybe? I have a normal cap tester not a high frequency unit.

Thanks in advance. I normally work on rockets or pinball machines, not
TV's.

John
Cocoa Florida

 

[Art]

Repair the vertical deflection circuit, esr the caps and change any that
check out of tolerance.

 

[Shoreline Electronics]

Did you resolder the output IC?


==========================
Jeff Stielau
Shoreline Electronics Repair
344 East Main Street
Clinton,CT 06413
860-399-1861
860-664-3535 (fax)
[email protected]
========================

 

[[email protected]]

Thanks Jeff. I'm thinking it is a cold solder joint, since the problem
is intermittent. Wouldn't a bad cap cause a problem that is always
there? The shrinking is only about 10-20% of the time. The rest of
the time the picture is fine.

Which one is the output chip?

John