Intellivision screen vertical shaking

[Ramses]

Well, I finally picked up an Intellivision this week and it's working okay aside from the screen shaking up and down after a while. It's sort of a jittery vibrating shake - the movement range is about a half inch to an inch. It initially started doing it after a minute of play and after I removed the tv switch box and connected the system directly to the RF input, it only starts shaking after about 10 minutes of play. I then tried swapping cables and connector adapters but it didn't improve any further. This is on a CRT by the way.

 

If I turn off the system and immediately turn it back on, it still shakes. I have to wait a few minutes before I turn it back on again for it to go away. Also not sure if it's related but in some games, there is a lot of screen noise whenever there is a loud audio noise in a game (for example when you enter a mountain in AD&D). Any ideas? I'm guessing maybe a defective capacitor or power supply?

Edited September 28, 2017 by Ramses

[mr_me]

Are you using a shielded RF cable? Sounds like the problem happens once the system gets warm. Does tapping the Intellivision do anything to the picture; warm or cold?

[Ramses]

Tapping it warm or cold doesn't seem to do anything. I'm using an unshielded composite cable with an adapter. I have one RF cable that's shielded but it's pretty old, banged up and working worse than the composite cable. I guess I'll picking up a new one and try that.