Well, I moved yesterday. One of the most triumphant moments of unpacking is re-wiring the entertainment center and finding that it still works perfectly, without having to jiggle anything or jostle any connections around.
But that triumph was marred yesterday when I turned the TV and VCR on. You know that lovely shade of blue that VCRs put on the screen when there’s no signal? It came up all right… but at the lower left and lower right corners of the screen, there are now bright red patches. They fade thru magenta into the blue at the edges.
When running a signal from the VCR into the TV, most images look OK. However, any solid blue background (and I’m talking the bluest of blue, as in #0000FF here) in any image also gets that red in the corners.
Is that something wrong with my TV? Maybe my VCR (no, I can’t really run a signal to the TV without the VCR involved)? Something I can fix???
You probably have some residual magnetic fields picked up during the move. The set needs to be degaussed. Many modern sets do this themselves during a “cold power on.” It might take a week before all the degaussing works. If the set doesn’t automatically degauss, then a TV tech can do it for not much money. Don’t try to do it yourself.
Make sure that there are no magnetic field sources near the TV now. Esp. unshielded speakers. (If you don’t know if they are shielded, assume they aren’t.)
There is a possibility that something shifted during the move and degaussing won’t help. If it’s something inside the tube like the shadow mask, learn to live with it. If it’s an adjustment ring on the next of the TV, a very well trained TV tech can fix it. But that will cost $. You may prefer to live with it as is.
While degaussing wouldn’t hurt, that doesn’t sound like the problem. The adjustment rings on the ‘neck’ are purity magnet tabs on the deflection yoke, and again don’t sound like the problem. To obtain white, the red, green, and blue screen and drive controls need to be properly adjusted, along with convergence. When one of them checks out of the hotel, you have 2/3 of the color.
It could be a plug connection which was jostled loose, but unless you have knowledge of TV innards, please stay outside. A CRT contains around 20kV, and will give a bite not quickly forgotten.
The deflection yoke is probably a smidge loose and has tipped down and away from the CRT at the bottom-hence the problem. Jusst the same, if you’re not familiar with the insides of a TV, lethal voltages are present.
Definitely check for other magnetic fields, as ftg said. We had the same problem with a speaker just above the left-hand corner, but it was only very noticeable during the blank #0000FF screen. Just find a different place for the speaker (or whatever) and it goes away immediately.