Used Naks for years, and one of the things that degrades is rubber rollers of every type, and grease or lubrication, which stiffens to the point of not being very useful at all. Other thing that degrades are contacts. Hopefully you are now where near the ocean. It takes years but I've actually had house light switches degrade so far they wouldn't work at all.
I also had a Yamaha CR-1020 receiver and after awhile most of the switches started getting intermittant. Took it to be serviced and the tech showed me a few of the contacts. They were all green and all needed to be replaced. First thing he asked me was how close to the coast was I. just something to think about
I would get it serviced before you have a problem, rather than afterward. better to be proactive than reactive.
Fiesta is dead on I had a Harman Kardon as well and it was very close to my Nak, which I must say I still miss.