Before you open the player up, are you still within the warranty period (1 year in the U.S., 2 years in the EU)? If so, contact SanDisk for a warranty replacement (you may need your receipt, to show that you’re still within the warranty period).
In the U.S.: 1-866-SANDISK (726-3475). And other SanDisk contact information: http://www.sandisk.com/sandisk-support/contact-us.
You otherwise might want to speak with the Customer Service people to see what they can troubleshoot.
