Ibanez tube screamer problem

[soundtechdan]

hi

I have recently pruchased an old version of the ibanez tube screamer the green one I think there the ones after the orginal. I have tried to use it but everything seem to work but its not very loud. So I opened it up and couldn't see anything wrong with it and I decided to clean the main sections. Everything works whenever I move the pots they work its jsut really quiet. Anyone recommend something cheers

dan