try disconnecting both battery cables and hold them together( away from the battery ) for a few seconds to clear caps, this could reset it. the radio may lock up and ask for a code after this procedure, make sure you can get this code. if the instruments comes back on the dash again try diagnosing the vehicle one more time to rule out a software issue with the tool. good luck

Just to add on also check all fuses see if there are no any fuse blown some times it could be cause when you plug in your diagnostic tool and it shorts the circuit..........