There is some sort of magnetic "wand" that TV repair personnel use for this purpose. Most new TVs do not need this.

Yes, but any such device would have to emulate the behaviour and have the power of an AC degaussing coil. There are two types of degaussing devices: AC (alternating current) and DC (direct current), which are commonly based on electromagnets. A magnetic field can be generated by passing an electric current through a coil - the electromagnet. The coil may have a hollow core, although a stronger magnetic field can be produced using a solid core made of a magnetic material, such as iron. An AC degaussing device uses alternating current to generate a magnetic field whose polarity alternates as the polarity of the input current alternates. The magnetic field is decreased over time, either by a control circuit or by slowly moving the degausser away from the device being degaussed. This helps to randomize any magnetic fields in materials in close proximity to the alternating magnetic field. A DC degaussing device uses direct current to produce a strong unidirectional magnetic field, which will induce a similar field in any magnetic materials that are in close proximity to the field. CRT monitors usually have a built-in AC degaussing coil that is activated when the unit is turned on. This helps to randomize the orientation of any magnetic fields in the monitor's shadow mask. These are induced by the presence of magnetic fields near the CRT. Magnetic fields in the shadow mask will cause the image to distort, because the electron beams are deflected by the fields before they reach the image phosphors. Therefore, an alternating magnetic field must be used to degauss a television tube. DC degaussers are normally used to erase magnetic tape and other magnetic media, which can be erased either by alternating or unidirectional magnetic fields. A DC degausser cannot be used with a CRT, because it will induce a magnetic field in the shadow mask. A randomized magnetic field can be produced by spinning a magnet on a shaft, for example, but the magnetic field these create is quite small. This method was commonly used in devices that were made to demagnetize the heads in cassette players. They did not work very well, because the magnetic field they generated was quite small.

Degaussing a TV clears electromagnetic buildup from the screen. Although it is hardly ever necessary, degaussing can sometimes slightly improve picture quality. Steps 1. Simply turn the TV off and turn it back on. Most modern TV's degauss themselves automatically each time they are powered on. When the TV is turned on, you should hear a distinctive "dwoing" sound. If you hear no sound when you turn the unit on, it may not degauss itself automatically. If that is the case, proceed to the next step. Bulk Tape Eraser Method The optimal tool to use, if and only if your TV does not have a built-in degauss function is a bulk tape eraser. This also uses a strong electromagnet that varies the magnetic field 60 times per second. 1. Hold the tape eraser about 12 inches away from the screen. Switch it on. 2. Approach the screen slowly, swinging the eraser around in a circle over the screen, until you see the field distortion. 3. Move the eraser away from the screen until you no longer see the distortion lines, then turn it off. Soldering Gun Method 1. Hold the soldering gun to that the rear of the case is toward the screen (the tip is facing away from the screen at a 90 degree angle) 2. Place the gun in the center of the screen and turn it on, keeping it near but not touching the screen (to prevent scratching) 3. Slowly move it to the top edge (or any edge), then slowly around the outer part of the screen (but still in front of the glass) until you return to the top (or the edge you moved out to), again slowly return the gun to the center of the screen. 4. Keeping the gun on, slowly pull it straight away from the monitor until there is no more distortion visible (usually 3-4 feet), then turn the gun off. Rigged Drill Method 1. Get a magnet and tape it to the end of a high RPM drill and make sure it is held in place very tightly, use Duct or packing tape 2. Hold the rigged drill next to the spot to be fixed, make sure it is about 2-3 cm away from the screen 3. Now pull the trigger an you'll see the screen blur fast, this is normal so do not worry 4. Whilst the drill is running, slowly pull away from the screen and you may see it is fixed 5. This process may need to be repeated due to magnet strength and drill speed but it will work 6. Due to physics the fast, random turning of the magnet/s will fix the screen's colors

thanks for the tips guys i had a green 'fog' on my sharp tv screen which gradualy spread from the top left corner and distorted the whole screen tried the soldering gun trick which helped a bit what worked best for me and sorted the problem out totaly was to run the soldering iron in a slow circle around the rear of the tv (around the back of the tube) one or two passes and the problem was sorted hope this helps chris

why the horizontal output is always blown while the power supply is okey

I know this was an old question but someone today may need an update and a cheaper way.... Take an electric pencil sharpener, put the backside up next to the middle of the TV screen,,start sharpening a pencil to keep the sharpener running and move it up to the top of the screen and then follow the edge of the screen 360 degrees back to the top spot and then back to the middle of the screen. Make sure the sharpener stays running the whole time. Once back to the middle of the screen, slowly move it away from the tv. I tried this and the first time it fixed most of the screen color,,second try and it fixed it all. No need to go out and buy an expensive coil.