my parrot mki9100 is not working?

Hi I fitted my parrot mki9100 in my car and it worked for a while, paired it with my phone all was ok, but suddenly it said goodbye on the screen and aint worked since, i purchased a new lead from blue box to lcd screen but still not working. i've checked to see if there is power to the blue box and there is. what could it be.

mark allen
June 2012