I had a radio, Airtronics Vanguard 6 that I hadn't used in 3 years and when I turned it on everything worked ok except for the throttle was glitching. The problem was the channel reversing switch; I don't think its worth the money to send in because it is 25 years old like your Expert 7. I have too many radios as it is and I been switching all my planes to 2.4 Ghz.