That doesnt mean the are blown per say

a coil may of gone bad which is repairable with a recone.

However if your amp is getting power and everything checks out try connecting another sub if you can find someone with one or a speaker (turn amps gain all the way down) and see if it kicks on

if it does then your speaker is bad, if it doesnt send me a picture of your wiring and ill find out whats going on.