Zenith TV Color intermittent

[zenith2134]

This is model B1926W made january 1986, is a great tv but I think (hope) it can be easily remedied by cleaning the controls. There is a switch called Color Sentry, which is flaky. The problem is that the picture gets overloaded and blurry with extrreme contrast and color, but comes back and sometimes goes black and white. This used to only happen when the control was manipulated but now it does it at random.

I did some research and found some modules that can cause this, but do you think I can repair these boards instead of replacement? Thanks