I'm soldering, couple of questions.

Hi there. Im soldering my RAMPS board. A couple of questions:

1. How do i check the capacitors are properly weld? So far, welded one and there is no continuity sound, but not sure if should be, it's a capacitor after all...
2. Tested a mounted led, there is continuity but the led does not turns on like the rest of the board, is it burnt?

Thanks!