Gotcha! Yes the 5080 is THE BEST tone control only boombox made. Panasonic balanced it just right so it cranks,has ample bass, clean trebles, but not overpowering either, especially if you want to crank it past 5 halfway, turn off Ambience, turn tone all the way to right and hit the gas! It pumps! I'm impressed with Pannys cassette player which use ample amount of actual steel, brass, aluminum on the decks, even the cheap ones in RX 4000 series work rock solid! Good luck on the Conion. I'm actually looking for another operational clean not abused Sanyo M9994. Yes....a Sanyo! I'm hooked on the build quality of that 1979 heavy hitter!
Also want to add that sounds like the record bar on the circuit board that gets actuated by record key on deck, gets stuck, could use some electronic cleaner or deoxit. That's why it suddenly worked from usage. After 30 plus years of not using record on these radios, things get stuck.