Posted by DerrickRe on February 21, 2002 at 22:46:59:
In Reply to: TV Discoloration posted by sam on February 20, 2002 at 08:47:16:
I am a certified TV Tech, and I get this complaint all the time. Doming is your problem. I assume the TV is 25" or larger.
CRTs (TV screens) have a metal mask with holes in it right behind the front glass. These holes allow the electron beam to land on the proper Red, Green or Blue phosphor.
The whiter the scene, the hotter the mask gets. This causes the mask to warp. Which causes the electron beam to not land completly on the proper color phosphor.
This is also why the colors get screwed up after dropping your TV. The mask shifts/pops out of place. If it pops out too far (from dropping) it becomes an X-Ray hazzard.
The only cure to doming is reducing brightness/contrast.
P.S. so People! Please stop harassing your local TV tech about doming (or other "My TV does not look as good as I want it to complaints"). There is nothing we can do. Putting in a new CRT may make it worse. It rarely gets any better. Remember we did'nt make the TV, or sell it to you. We have no control over it. TVs are not a perfect viewing experience, despite what your salesman sold you on. So, torment your salesman and TV manufacturer instead. Rant complete. :-)