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Is it just me, or does the article not actually answer the question in the title? It explains the components well, and how a magnet distorts the image, but does
by lukev 3y ago
Is it just me, or does the article not actually answer the question in the title? It explains the components well, and how a magnet distorts the image, but does not describe which component is capable of being permanently altered by an external magnetic field.
Is it the phosphor coating? The deflecting coils? Some sort of static field in the glass?
- db48x 3y agoA magnet will bend the electron beams, but that isn’t permanent. A permanent color change made by a magnet only happens by imposing a magnetic field on a metallic component of the monitor, so that the beam is always deflected by it. One component not shown in that diagram is the shadow mask, which divides the screen into discrete dots to be activated by the electron beams. This is a very thin piece of metal (or a grid of thin wires in certain cases) that is easily magnetized.
- joezydeco 3y agoAnd can be repaired, most of the time, with a degaussing coil. https://youtu.be/3pVLizAHby4 https://youtu.be/3pVLizAHby4 There was a time with some of these larger TVs and monitors where a coil was built into the frame and would energize briefly on power up, or with the push of a button on the control panel.
- lukev 3y agoOh yes, I well remember the "degauss" button on CRT monitors. We had one where it was basically a mini EMP and would make the images on nearby monitors quiver as well. Fun times. I know a magnetic field was being retained somewhere, just wasn't sure which component it was.
- ksaj 3y agoEverybody loved the degaussing sound and visuals. Young people don't know what they're missing.
- lopis 3y agoI can't believe the author skipped this part. I felt terrible unsatisfied with the article. Thank you!
- db48x 3y agoYou’re welcome
- duskwuff 3y ago> This is a very thin piece of metal (or a grid of thin wires in certain cases) that is easily magnetized. Worse, a strong magnet (especially a modern rare-earth magnet) can bend the shadow mask, causing color distortion which can't be corrected by degaussing.
- nneonneo 3y agoOh my goodness, I wonder if that’s what I did to my parent’s TV as a kid? I remember clearly playing with a large hard drive magnet near the TV and causing the TV to change colours - we ended up with a purple blob in one corner that never went away even after many rounds of degaussing and power cycling.
- db48x 3y agoYup. That’s exactly what you did.