How do I get a broken Rio Carbon MP3 player fixed?
Throw it out. If you don’t have the time or knowledge to fix it yourself, any non-battery problem means it’s effectively trash. Like an Ipod, it’s designed to break with a non-replaceable battery, and unlike the Ipod where you can still feasibly buy a new battery and void your warranty putting it in, it seems like working around this instance of corporate malfeasance is less practical than just buying a new MP3 player: I have chased the battery manufacturer in China and as the Carbon batteries were custom made for Rio there is no equivalent available. It would be easy to find a battery with close enough electrical characteristics, but depending on how custom the battery design was it will probably be hard to impossible to find one that properly fits the case.