magnavox big screen

How big are the yellow spots ?

kip

Yellow spots are actually lack of blue. First check and clean the accessible optics. Bugs sometimes get into the lens assemblies, spiders build webs inside the box, dust and other contaminants get on the lens, mirror, and screen.

Beyond that is the blue tube itself, which has two common problems:

1. There is a bacteria or algae that can survive the glycol environment in the cooling chamber, and it especially likes blue light. An amazing amount of growth accumulates over time which blocks and scatters light. Cleaning and fluid replacement is indicated for this. Affordable.

1. The blue phosphor is the least efficient, so the blue gun is driven harder than the others, and the screen becomes "burned" over time and gets dimmer. If the burning is excessive or uneven, you start getting uneven illumination. CRT replacement is the only cure for this. Very expensive.

An experienced servicer can tell quickly which of these problems you have and give you an estimate.

How big are the yellow spots ?

the screen, and are very noticable when the picture is white or very light. i have cleaned the lens on the tube but nothing changed.