My NAD 7100 FM & AM receiver is acting like there is no antenna connected - barely a signal on even the strongest stations. It has a good antenna with good, clean connections and I have substituted another, duplicating the same symtoms. The amp section works fine for the CD & tape players. Can someone help me get started troubleshooting this? I have electronics trainiing, albeit many years ago. I have only a basic multi-meter now. any help would be appreciated. TIA, Tom L.