Need some expert help with this rca Tru flat

[[email protected]]

So I picked up this set from a friend who described it only as "it
works but the colors are weird"

http://img63.imageshack.us/img63/4204/rcatruflatgx4.jpg

I've checked the degauss circuit, any leaky caps etc etc and am coming
up empty--anyone have any thoughts as to what this particular failure
mode might be from? Its a 27" RCA tru flat. Of interest is that when
its dark the color bands aren't as close or bright but when its light
the color bands get closer together and more distinct.

thx in advance!

 

[Meat Plow]

So I picked up this set from a friend who described it only as "it
works but the colors are weird"

http://img63.imageshack.us/img63/4204/rcatruflatgx4.jpg

I've checked the degauss circuit, any leaky caps etc etc and am coming
up empty--anyone have any thoughts as to what this particular failure
mode might be from? Its a 27" RCA tru flat. Of interest is that when
its dark the color bands aren't as close or bright but when its light
the color bands get closer together and more distinct.

thx in advance!

Do the bands move?

 

[[email protected]]

Do the bands move?

in a fixed image the bands do not move--they do move as the picture
brightness increases or decreases.

 

[Meat Plow]

in a fixed image the bands do not move--they do move as the picture
brightness increases or decreases.

Odd, haven't seen one like this that I can recall. Hopefully someone will
chime in with a clue as this has sparked my curiosity.

You didn't try to manually degauss it did you?

 

[[email protected]]

Odd, haven't seen one like this that I can recall. Hopefully someone will
chime in with a clue as this has sparked my curiosity.

You didn't try to manually degauss it did you?

No i tested the degaus circuit and it operated as it should. I also
replaced the "tv on a chip" IC thinking maybe the color signals have
been corrupted--made no difference. Trouble is I've never seen
anything like this so not sure where to start.

thx for looking though!

 

[Meat Plow]

No i tested the degaus circuit and it operated as it should. I also
replaced the "tv on a chip" IC thinking maybe the color signals have
been corrupted--made no difference. Trouble is I've never seen
anything like this so not sure where to start.

thx for looking though!

If the tube has been severely magnetized the degauss circuit won't help.
Was the set dropped? Maybe something inside the tube came loose.

 

[Chuck]

So I picked up this set from a friend who described it only as "it
works but the colors are weird"

http://img63.imageshack.us/img63/4204/rcatruflatgx4.jpg

I've checked the degauss circuit, any leaky caps etc etc and am coming
up empty--anyone have any thoughts as to what this particular failure
mode might be from? Its a 27" RCA tru flat. Of interest is that when
its dark the color bands aren't as close or bright but when its light
the color bands get closer together and more distinct.

thx in advance!

Looks like a bent shadow mask in the CRT. Set has probably been
dropped. Chuck

 

[Andy Cuffe]

So I picked up this set from a friend who described it only as "it
works but the colors are weird"

http://img63.imageshack.us/img63/4204/rcatruflatgx4.jpg

I've checked the degauss circuit, any leaky caps etc etc and am coming
up empty--anyone have any thoughts as to what this particular failure
mode might be from? Its a 27" RCA tru flat. Of interest is that when
its dark the color bands aren't as close or bright but when its light
the color bands get closer together and more distinct.

thx in advance!

It looks like it was dropped to me. The only other possibilities I
can think of are the degaussing circuit, or the yoke has moved back on
the neck.
Andy Cuffe

[email protected]

 

[S]

It looks like it was dropped to me. The only other possibilities I
can think of are the degaussing circuit, or the yoke has moved back on
the neck.
Andy Cuffe

[email protected]

So I read "bent shadow mask" as "tube is hopelessly fubared" --I'll
give the yoke a tug and see if its loose at all--doesn't appear to be
from what I recall but worth another look I guess. Thanks for the
feedback guys!

 

[Franc Zabkar]

So I picked up this set from a friend who described it only as "it
works but the colors are weird"

http://img63.imageshack.us/img63/4204/rcatruflatgx4.jpg

I've checked the degauss circuit, any leaky caps etc etc and am coming
up empty--anyone have any thoughts as to what this particular failure
mode might be from? Its a 27" RCA tru flat. Of interest is that when
its dark the color bands aren't as close or bright but when its light
the color bands get closer together and more distinct.

thx in advance!

Smack the face of the CRT with the palm of your hand. If the patterns
vibrate, then I'd suspect a damaged shadow mask.

- Franc Zabkar