Hello. I have recently purchased 4 Kenwood TK-840 radios on ebay, I am able to program 3 of them but the 4th powers on and flashes "UNPROG" and I can not figure out how to get it to go into program mode from either the software or the radio itself. Any suggestions? Is the there a special key combo I need to hold while I hit the power key? Is there a jumper inside I can reset it with or something? Any help is appreciated. 73's K0LTN