i followed this thread viewtopic.php?f=33&t=25465 .............and now my unit will start up with a blank screen and when i press menu i get to the menu but now of the buttons on it work except destination when i press destination the unit goes to the next screen and freezes also it is turning on and off every 3mins.....what do i need to do to get the unit to fully boot up and work.....prior to this problem i was in the service menu and pressed format mbr and the unit would boot up and shut off right away