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" wrote in message
...
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" wrote in message
...
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" wrote in message
...
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...