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Can magnets permanently damage CRTs?

I have a 1978 RCA XL-100 TV that I use in my main HT system. It's obviously a CRT and it's solid state. Without naming names, I'll just say that a demonstration of a magnet's effect on the picture tube was performed. Now the picture remains distorted even though the magnet is far away from the TV.
My question is whether the magnet just temporarily affected the CRT's stability or is the CRT ruined?
hals_den
hals_den OP
77 posts
 
Thank you guys for your advice. I did "the google" on CRTs and magnets and I will try to degauss the picture tube. I tried a tape head demagnitizer and it changed the color distortion. I think I'll just grab the next discarded TV I find on the street and open it up and see if it has a degaussing circuit I can cannibalize, and make a degausser.
Howell
hals_den OP
77 posts
 
I just bought a heavy duty degausser on ebay for $24.
ellery911
549 posts
 
A long time ago I set a raw car speaker on top of my television. I didn't think much of it until a few days later the picture was looking a little strange...not extremely noticeable...but different...the colors were a bit off.

When I picked the speaker up off the set...BAM...the colors were all out of wack...completely...not to mention the "stretching" of the picture.

Luckily...a good friend was an EE and explained to me that the picture had "aligned" itself with the magnet and within a few days it would realign itself.

He was right...after a few days...it was back to normal.
elizabeth
6,726 posts
 
Can magnets damage a CRT: yes.
Do most fix themselves: yes.
Most modern CRT's automatically 'degauss' at turnon. Your old screen may not have that feature.
A large looped wire with at least six loops with an AC current flowing in it will fix your screen.
You can use a LONG extension cord and make it into a perfect circle 20" diameter. At least six loops, better ten, and let it be in use running some big current draw item.
the loops should be rigid!! use a coathanger wire as a form.
Take this contraption and bring it (while powered) near you TV screen.. moved it slowly!! slowly around and around the turned on TV screen. VERY close! 1 inch away. Then slowly very slowly move the coil away from the screen while both have current running through them. DO NOT TURN OFF THE COIL NEAR THE SCREEN!!!!!!!!!!!!!!!!
This should fix the worst old TV magnetization.
fatparrot
1,314 posts
 
As Elizabeth said, don't forget to include resistance [light bulb in a socket will work] in your home-made degausser, or the TV will be the least of your problems!
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