I bought SanDisc month ago and till today everything was fine. I was using it mostly to listen to audiobooks. Today sound became rough and slow. I removed all files and formatted mp3 player but sound is still the same. BUT when I copied audiobook to music folder sound is clear and normal. How to fix it? Where is a problem?
Perhaps try manually reapplying the latest firmware? Glitches can develop over time.
See the firmware sticky thread at the top of this forum.
when playing an audiobook, that is stored in the audiobook folder, if you press the bottom button with 4 lines it will open the submenu. Here you can change the play speed of the book. Slow, Normal, an fast. Make sure you have not inadvertently changed the play speed to slow.