Another old guy DIY'er

Been a DIY'er all my life cause I like fixing things. Built a 32 Ford Roadster from the ground up for one example. I went through Conn. School of Electronics back in 1959 and 1960.
Probably forgot more than I learned...LOL
But anyway...I now have a Denon DCM-320 thats got multiple symptoms and I'd like some direction as to where to go.