Degauss TV screen

Yes, there is a tool called a "Degaussing Coil" (imagine that!!!). You can buy one from online vendors

Other vendors might also stock them... Google for "degaussing coil"

Leave it be. It will fix itself. Unless you know what you are doing you may make it worse.

If you do know what you are doing try a video tape degausser with the usual precautions.

I have a set of coils salvaged from a monitor. It was wired for direct 110v operation via a thermal resistor to shut it off after initial power up and degaussing. Can I just wire a standard 110v plug with a N.O. push button switch instead to zap anything that needs clearing up?

Dho! It fixed itself. Thanks everybody! Let's all get degaussed!

you can try to erase it using the same magnet reversed, this won't be perfect,

or give it a few weeks, it'll fade gradually.

Or if you're in a hurry you can erase the mark using an ac powered electromagnet.

Or take it to a TV repairman, it's a 2 minute job.

Bye. Jasen

If you have 110V (ish) AC, then yes. if it gets hot let it cool down.

Bye. Jasen

Can anyone here explain how it did this? That is, how did a TV affected by a magnetic field clear itself without any outside help?

Perhaps it has a built in degauss coil like many CRT monitors. They are activated at switch on so power cycling it a few times may have fixed it.

All color TVs have a circuit to do this which runs once when you switch on. If the magnetization is severe it may take a few times.

All crt tv's have a built in degaussing circuit. They use a PTC (positive temperature coefficient) resistor to limit the current through the degaussing coil. Therefore when the TV is first turned on, the coil sees a large current, as the PTC heats up the current decreases (resistance increases) until it reaches a very low current that won't affect the CRT deflection. When the set is turned off, the PTC cools down, lowering it's internal resistance for the next TV turn on. If you just cycle the set normally eventually it should correct itself.

They use a type of steel that doesn't retain magnetism well, there is also a degaussing coil attached behind the screen (it's what makes the "fong" sound when you turn the set on)

Your TV's internal degaussing coil should eventually take care of the problem. After a number of power cycles over a period of time should clear it up. If you turn the set off for about an hour, and turn it on, the degaussing coil should activate. I would not suggest cycling the set's power on and off specifically to degauss the screen. Start-ups are hardest on any electronic devices.

The quicker and more sure way to degauss the screen is to get a degassing coil that is designed for that purpose. Any of the TV service people who have been replacing CRT's and servicing TV sets, should have one. See if you can put down a deposited to borrow or rent it, or simply have their tech come over and degauss your set. The service call would probably be cheaper than buying one that you may only use one time in the life of the set. Your next set will most likely be a Plasma or LCD type screen. There are no degaussing problems with these.

Sometimes, when a magnet is swiped across a CRT, the mask can be damaged. If this is the case, then the damage is permanent, and the only fix is to replace the CRT. A CRT replacement is not worth the money for any consumer set.