Electric Guitar not making noise

I recently left my guitar at school when i was away, and when i come back, it wont make any noise when i plug it in. Im not sure if it is a pot problem or a more serious electrical issue. apparently, my friend was playing it, and turned the volume nob down to talk to someone. when he turned the nob back up, it wasnt making any noise. Does anyone know what the problem might be? should i take it in or could i fix it myself?
Much appreciated

It might be that the volume knob has worked lose and twisted underneath snapping the wire off