Whoa. I didn’t know you could do that to a TV.
Once this is all sorted out, get that kid some physics toys and teach him how to be a responsible scientist. He could go far. 
Thanks for correcting my bit of misinformation, hammerbach. 
Neither one is actually distorted. Something in the tube (and yes, it’s probably the shadow mask) is magnetized, and this is bending the electron beams slightly. Degaussing demagnetizes everything. As stated, most tubes degauss a bit when turned on, but this is slight and intended to correct itsy bits of magnetism picked up from normal use, not up-close-and-personal exposure to magnets. It may correct that, too, over time. A degaussing coil will do it quickly. The coil works by creating a strong field, reversing it, then a weaker field, reversing it, and fading down to no field, all in a period of seconds. You can do the same with a permanent magnet if you are careful, but a degaussing tool is probably cheap. If you live in a big city, try someplace that repairs nice monitors. They will have one. Maybe someplace that has sold TVs for a long time still has one around, from when they were worth repairing.
This happened spontaneously to a TV at my house. I wasn’t able to completely remove it by reversing the polarity (taking tech lessons from Geordi LaForge) but I got it watchable and ended up leaving little magnets taped to the side of the TV to keep the colors stable.
audilover!
The vacuum thing didn’t work, sorry guys. I did try it.
Turning it on and off (with unplugging) didn’t work.
But using the magnet that caused the trouble did work! Yay!
Thank you audilover, and thank you all for you responses and help! The SDMB saves my ass again.
You’re a very brave person, carlotta.
You’re quite welcome, and I’m very glad to be of service. I did learn a few handy lessons from my mischievous youth.
Egad, I’m off the board for a couple days and THIS thread appears.
Here is the Real Info by a real pro on do-it-yourself degausing. Do not attempt anything listed in this thread unless it is given in Sam G.'s faq.
My 5yo nephew did this to the TV recently, it fixed itself after a couple of weeks.
On similar magnet related issues, I came to work one day to find my boss very distressed that all the information prior to the preceeding Friday had disappeared on his computer and now his PC was acting very strange. After much attempts at fixing it I sat back and had a look around his office only to notice a magnet stuck to his computer! Someone had given it to him on Friday. :rolleyes:
I’m not impressed…the OP said that she tried the power cycling technique, and it didn’t work. She also said she’s already tried my method of using the permanent magnet, with excellent results.
I have no doubt that a real degaussing device work, but if she wanted to go out and buy something, she wouldn’t have asked the question in the first place. Obviously, the permanent magnet used in the above described manner works just as wel as a fancy oscillating electromagnet. It’s never failed me…ever. And I’ve magnetized quite a few CRTs in my time.
Just to back up audilover, when I lived in a house full of engineering students we managed to utterly wreck our TV when someone decided the homemade bass woofer should be placed on top of it. One of the bright boys I lived with took a look at the problem, walked into the kitchen, came back with a refrigerator magnet and fixed the problem in five minutes.
Hehehe… External magnetic shielding with fridge magnets? Bonus points!