Problem with CD playing through...

Hello to all...

I'm having a problem with my CD player playing CDs all the way through: 

Marantz SA-8001 - have about 10 years (purchased used).
Played fine until about 6 no. ago, when it started to skip on the playing disc and not reading others...
Never turn CD off; clean discs with a soft cleaning cloth before playing; use Maxwell CD cleaning disc about every 10 hrs; sometimes use buttons on unit but mainly use remote to open/close, repeat or reply tract...

Discs that I've had for years have stopped in mid-song or more upsettingly, suddenly sound like they are being ground up insider the player! Then sometimes the music continues to again play, sometimes backs up and replays, sometimes just stops playing with no sound...

Anyone - HELP! Ideas, Suggestions, Examples, Experiences - or reasonable suggestions. No money for a new player - I need to figure out a home fix or if worse, a n expensive trip to diagnose...