Accidentally got 6.3v 47uF tants when I thought they said "63v". Doh! Is there anywhere that it's safe to use these? Maybe Pin 2 on a Pt2399 delay (e.g. C13 in the Cave Dweller) - i.e., anything after a 5v voltage regulator?
Yes, after a 5v regulator it's fine. Problem would be if that cap ever saw higher voltage it could be very bad.
Jacob