I recently purchased a used Iwatsu SS-5705 (my first) and it seems to
function correctly on all 3 channels. I have noticed that when I turn
some of the knobs it behaves like there are dirty or loose contacts.
What is the best way to go about cleaning/checking the guts of the
machine? Is it just a matter of using a contact cleaner or should I be
on the look out for cracked/cold solder joints?

Also does anyone know where you can hunt down manuals for these older
units? The company itself still exists and makes scopes but they don't
go as far back as this unit in the on-line library.