It's worth getting it checked out. I've only fixed one R75, all it had was a cracked resistor that I found with the freezeit spray. Five minutes later, it was working fine. It only took about 3 hours to find it. The radio would work fine for about 10 min, then go almost totally deaf. The owner took it some place that couldn't find the problem, and I did, and I'm no means a pro, just someone who has messed with old radios for over 55 years. I have fixed a lot of R71A's, most of the problems with those were power supply related, or the caps needing replaced due to the heat the radio generated from running it on AC power. I got a couple of new unused PS's off Ebay for about $25 each, and got them running, but running them on 12V is the really smart thing to do. The R75 doesn't have that problem as it doesn't have a built in AC supply.