i'm guessing the rear projection television described above uses three crt guns (red blue green usually)
- one of the crt electron guns might be failing
- maybe a piece on the circuit board is old and failing (or maybe an entire circuit is old and needs replaced)
- maybe a controller chip has failed
it goes like this:
the circuit is used to power the crt gun
the controller is used to control the circuit
now, that controller might be in direct control of the crt gun
the controller might be closer to the cable input for receiving and 'decoding' the signal.
the problem might be any one of the above, or even perhaps one of the crt projectors needs the gas refilled.
i've seen crt displays opened up and have had gas put inside.
i was too young to know (remember) if the gas was to provide proper functionality
if the gas was supposed to save the crt phospher from burning in an image.
it might be an easy fix.. but it might require more trouble than it is worth.
for instance, if one entire circuit is bad (the levels are low) you could replace that circuit and find that the next circuit in the chain of events is too old and aged to function properly with the replaced circuit (meaning the levels are not fresh like when it was new)
this means the circuit would have to be custom made to work with the other aged circuit.. and the other aged circuit might fail sometime soon in the future (makes the entire repair worthless)
if you really want to know, an electrical repair shop should charge about $50 to take the television apart and learn what is wrong and what needs to be done for a solid repair.