PANASONIC Color problem "circle"

[Max]

Hi all,

Having a Panasonic television CT-27... with a color problem. There is a kind
of big circle on the screen and the color is not right around thiscircle.
King of purple and yellow.

It looks like a perfect circle so I'm assuming something in the tube itself
is bad. Shadow mask ? Problem with the Degauss ?

Any idea ?

Tks for you help...

 

[b]

Hi all,

Having a Panasonic television CT-27... with a color problem. There is a kind
of big circle on the screen and the color is not right around thiscircle.
King of purple and yellow.

It looks like a perfect circle so I'm assuming something in the tube itself
is bad. Shadow mask ? Problem with the Degauss ?

Any idea ?

Tks for you help...

someone probably put a speaker or other magnet against it or it is
impact damage.try replacing the degauss posistor first.
-B

 

[Dave Plowman (News)]

someone probably put a speaker or other magnet against it or it is
impact damage.try replacing the degauss posistor first.

The built in degauss won't fix a bad case. Needs external degaussing. A
repair shop should be able to do this.

 

[Sam Goldwasser]

Hi all,

Having a Panasonic television CT-27... with a color problem. There is a kind
of big circle on the screen and the color is not right around thiscircle.
King of purple and yellow.

It looks like a perfect circle so I'm assuming something in the tube itself
is bad. Shadow mask ? Problem with the Degauss ?

Was it dropped?

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[Max]

The unit dhas not been dropped and no speaker has been put near the TV.

Unit was OK and went bad just like that.

You can easily see a big circle in the middle...

 

[Andy Cuffe]

The unit dhas not been dropped and no speaker has been put near the TV.

Unit was OK and went bad just like that.

You can easily see a big circle in the middle...

In that case I would say that either the degaussing circuit has
failed, or the deflection yoke is loose and has slipped back on the
neck of the CRT. Both of these problems are minor and will cause the
problem you describe. Manual degaussing won't fix either of these
problems.
Andy Cuffe

[email protected]

 

[[email protected]]

In that case I would say that either the degaussing circuit has
failed, or the deflection yoke is loose and has slipped back on the
neck of the CRT. Both of these problems are minor and will cause the
problem you describe. Manual degaussing won't fix either of these
problems.
Andy Cuffe

[email protected]

in some cases moving of scan coils back can result in tube explosion.


NT

 

[verni]

Hi all,

Having a Panasonic television CT-27... with a color problem. There is a kind
of big circle on the screen and the color is not right around thiscircle.
King of purple and yellow.

It looks like a perfect circle so I'm assuming something in the tube itself
is bad. Shadow mask ? Problem with the Degauss ?

Any idea ?

Tks for you help...

have u tried degaussing with degauss ring..
if not try an ordinary magnet to see if it corrects problem..if it does then replace degauss component inside tv( this will be the thermistor) usually located near power supply...tv's usually degauss the moment they are swithed on...however a bad degauss usually creates coulered patches around edges.. vernon

 

[BH]

in some cases moving of scan coils back can result in tube explosion.

NT

In some cases dropping a CRT onto concrete can result in breakage,
Huh??

Bruce

 

[Leonard Caillouet]

Circular magnetic effects are usually due to the degaussing circuit
malfunctioning or a power surge such as happens with a nearby lightning
strike. The former is very common on Panasonic sets, could be bad solder
connections at the degaussing thermistor or a bad thermistor.

If it is the latter problem, manual degaussing may be needed.

Leonard

 

[Max]

Hi All ,

The thermistor has been tested OK and solder joints are OK.

How to confirm that it's not the tube ? Shadow mask ?

Should I try to degauss it anyway ?

Tks for you help...

 

[Leonard Caillouet]

You may have had a nearby lightning strike? We see sets all the time that
have been subjected to a surge that have the tube magnetized by the
degausing coil to the extent that the internal degaussing cannot demagnetize
the tube.

The fact that it is circular indicates that the source of the magnetic field
is likely the degaussing coil itself. A damaged CRT shadow mask will almost
always give you adifferential symptom at the edges on one side.

Leonard

 

[Max]

Right on !

I use an external degauss coil and it's OK now.

Tks.