First thing I would do would be to take a multimeter and some spare wire and check to make sure you're actually getting 12V/2A out of your VRM. If you're not getting anything, you found your problem. Otherwise, put your black multimeter lead on the pin inside the barrel connector, and your red one on the outside. (You might get a negative number. I forget which is ground
). If you get nothing here, but you got something from the VRM, your problem is the cable. After that, if all of this works and your radio still doesn't get power, your radio is probably dead.