What could cause this?

[SpaceAge]

I have a Sony TV-VCR combo model KV-13VM30, manufactured 12/96. It was a $1 garage sale purchase about five years ago, and it has had problems since the day I bought it.

When I first power it on, the picture appears too bright, with poor contrast. I played the opening sequence from Star Wars on it, with the text scrolling up the screen. The background is black space and should be completely dark, but instead appears gray and washed out. In addition, there is a bright band on the far right edge of the screen, about a quarter inch wide, top to bottom. After about 15 minutes of use, the picture will begin to shake side to side very noticibly. Turning it off and then immediately back on will not fix this, I have to leave it off for a while and let it "cool down." Given enough time, I can turn it back on and the get back to where I started. After 15 minutes, the shaking will return. The issue happened regardless of the input. The VCR seems to work fine.

I opened it up today to take a look, and a few things stand out. Several large caps seem to be held in place by blobs of white silicone. Someone must have used the silicone to hold the caps in place, and then turned the board upside down and soldered the bottom. I doubt this is original, since the silicone blobs at least partially cover neighboring resistors. No way do I believe it was like that when new. Also to note is the label on the tuner is printed "NOV 09", I assume that's a date code. So apparently this thing has been worked on relatively recently.

If anyone can advise, I would appreciate it. This thing isn't vintage or particularly interesting, but I want to at least give it a chance and try to fix it. I could post a video of the problems on YouTube, if that would help. Thanks