hi and welcome to the forum, there are a few things we have found out, and only last night I was thinking all these tips and tricks need to be compiled into one thread. I shall start doing just that when I get home, unless somebody else wants to make a start.
Put the key in ignition and power on, then off, remove key, repeat three times in quick succession. That is what I had to do to reset mine when it froze trying to view gallery of my windows phone. It may not work but worth a try?