Commodore VIC-20 color going in and out

[retrobecanes]

The color on my VIC-20 is going in and out, I adjusted C3 to regain it but it is not stable and a little finger pressure on C3 is enough to affect the color.
Now when I turn the VIC-20 on, it has color but then I played with the computer for 10 minutes and it goes to black and white.
I turn the computer off and back on, and the color is back. Then it goes off again after a few minutes.
What can I do?

 

[jltursan]

Reflow C3 soldering just in case; if nothing changes, replace it, seems to be a bit flaky.

 

[czunit]

I was thinking the same thing: The variable capacitor may just be shot after 40 years. Maybe try cleaning it with Deoxit or somesuch as well.