Mp3 player not recognized

[Liater]

Hi, I bought a swimming mp3 player. Connected to my Mac , downloaded some songs . Second time my computer didn’t recognized my mp3. I tryed on my second computer that is pc and nothing. I bought a different mp3 player for swimming and it happened the same, at the first time the computer recognized it, second no

 

[CP30126]

What is their model number? Perhaps they have to be set to file transfer mode if you want to open their memory to the computer.