19 May
2012
19 May
'12
1:01 a.m.
David Riley wrote about color CRTs:
Yep. Definitely had more than one that was permanently
discolored
because it didn't have one (until I fixed it manually). I don't think
our warranties cover that damage (it'd be classified as abuse).
No, if a color CRT TV or monitor doesn't have a degaussing coil, it will
have color problems every time you physically reorient it with regard to
the earth's magnetic field, or any other ambient magnetic field. My
friends that did TV repair for a living for many years say that they
have *never* seen a commercially sold color CRT TV or monitor that
didn't have a built-in degaussing coil, even in the cheapest ones.
The degaussing coil in the monitor is relatively weak. If a strong
external magnetic field is applied, it may affect the CRT more than the
built-in degaussing coil can correct. In that case a more powerful
external degaussing coil is required. People that did TV service had those.
If a *very* strong external magnetic field is applied, it can
permanently warp the shadow mask or aperture grille, in which case no
amount of degaussing will fix it. This was sometimes seen when people
accidentally discovered that holding magnets near the face of the tube
produced interesting visual effects, without realizing that they could
permanently damage the tube.