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(Magnetic disturbance) colour spots on an old TV screen

(Magnetic disturbance) colour spots on an old TV screen

(Magnetic disturbance) colour spots on an old TV screen

(OP)
My dad bought an old Television set at a garage sale, but it looks as though somebody took a big magnet and messed around with it on the picture tube. Ive got a green tint along the top and a purple spot on the right side. I used the magnet on the back of an audio speaker to temporarily negate and fix the problem by passing it near the screen, but the problem came back as soon as I took it away.

if anybody can help, I need to get rid of these magnet colour deviations (usually caused as well as fixed with a magnetic device) on my dad's TV set.

RE: (Magnetic disturbance) colour spots on an old TV screen

The fast answer is, deauss the set.  Since you probably don't have a degaussing coil, you can use a hand-held soldering iron to produce a varying magnetic field.  Turn on your soldering iron at a distance of about three feet from the TV screen, and then move it in close to the screen.  You will see the rapidly varying magnetic fields displayed as changing colors on the TV screen.

Wave the soldering iron circularly around the screen, especially over the affected areas.  Then, gradually move the soldering iron away from the screen.  That will remove stray magnetism that has built up on the picture tube.

This will only work with a transformer-powered soldering iron, such as a Weller 8230N or equivalent.  Pencil irons have no strong magnetic fields associated with them.

If you see improvement, but there are still color splotches, try repeating the process.  If it gets better, but doesn't clear up altogether, you may need a stronger degausser, or you may need to perform a complete purity alignment.  Also, the set may have been bounced around and the yoke might need adjustment.

Hopefully, the soldering iron will do the trick.  Remember to make sure you move the iron at least three feet away from the screen before turning it off!  Otherwise, you might magnetize new portions of the CRT.  

Have fun with it, and good luck!

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