'88 Toshiba CF2647 video problem

[radiotvnut]

On a "no signal" condition, the CRT has snow and the brightness is normal. When a signal is applied, either at the antenna terminals or at the A/V input jacks, the video is very dark with streaks and black splotches in the picture. I can turn up the sub brightness to make the picture brighter; but, it is still streaky with the black splotches. I have the sams photofact on this set and have already checked several caps and transistors and I'm getting tired of fooling with it. I just thought I'd ask someone on here if they'd ever seen a similar problem before I junk this one.