This is a sketch of what my TV looks like sometimes. The blue and yellow areas appear and disappear at random but always in the same place. It’s a Magnavox 27" about 10 years old. Any ideas?
Do you own any degaussing equipment? If so, you might try degaussing
the screen.
Could be a magnetic field from some other piece of equipment deflecting the electron beam inside the TV. That can cause it to hit the wrong phosphors, giving a color shift.
Are there any appliances, machinery, or electronics nearby that have electromagnets inside – e.g., loudspeakers, motors, compressors, etc. – that turn on about the same time as picture distorts?
Look for metal near the screen, too. That looks just like the screen of the TV in my classroom, except the colored patches are at the bottom. They show up at the end of a video sometimes, but all I have to do to get them to go away is shut off the tube for a bit.
Maybe you’re picking up the Abstract Expressionist Channel.
It’s called a purity fault. Could be cause by strong nearby magnetic fields (loudspeakers) or the set could have come near a strong magnetic influence and retained some of the magnetism. You can get a degaussing coil for around $20 to clean up the problem.
Mine does that too. It’s a Magnavox but smaller than a 27", I think. I haven’t really noticed the blue but any large white patches of the screen have that yellowish tinge to them. There’s also about a two-inch wide “wave” about a third of the way down the screen, which seems to get a lot worse when the picture has strong horizontal elements, like a window with blinds. Causes people’s heads to distort, looks kinda freaky. I never thought about degaussing, I just figured the picture tube was on it’s way out… Of course it’s been like that for the last two or three years.
The purity issue has been mentioned, but if degaussing doesn’t solve the problem, going back to when I worked on TVs, there were purity rings which had to be adjusted on the yoke prior to dynamic convergence. If the set has been moved (any distance-not cross the room), the rings may require a tweak to eliminate odd colored fields.
If my husband has his amplifier too close to the television, it’ll make that happen to the screen.
As others have said this is often caused by having a magnetic field too close to the screen. It can also happen just by moving the TV set or by some other means of vibration.
I think most TV sets made in the last 10 years or so automatically degaus the screen when you turn them on. Try turning it off and then back on about 10 minutes later (but not with the remote, actually turn it off at the wall). This may fix it, otherwise you will either need to get a degaussing wand or a service call.
Thanks for all the advice. There’s a fair number of electronics within 6’ of the TV that might cause a magnetic field – VCR, PC, clock radio, stereo & speakers, two printers, a fluorescent desk light, and a couple of fans. Then on the other side of the wall there’s another TV, VCR, and stereo. I guess I have my work cut out for me in finding which one(s) are the culprit.
Removing the culprit may not be enough. Once a colour purity problem occurs it usually stays until the set is de-gaussed.
If you want to trouble-shoot the cause of the distortion set the tv screen to a solid blue (like a menu screen from the vcr) then wiggle various pieces of equipment that are around the tv.
The culprit will be the unit that makes those colored waves move. Most likely loudspeakers,