Interesting that you were able to at least get as you have on your own.
I am not optimistic for you. My guess is that it’s off warranty. I had just an awful experience with Marantz customer service a few years ago. You may want to investigate independent repair services in your area after trying to deal with Marantz.
I will also note that I have owned multiple CD player in the last 4 decades. Never had a problem with any of them. Of course something may have happened depending how you stored it the past few years but assuming that you didn’t do anything freaky and wasn’t left to bake in an uncooked shed, or tossed about in a hurricane, any decently manufactured product should be working