Charging problems

Just purchased a Sansa Fuse+ 16G, When I plug into the USB screen indicates connected. It will be OK for 1 minute or so, then the screen goes dark and I loose the USB port (Fuse icone gone from media player). If I pull the cable & wait 20 sec or so, then reconect, the Fuse+ comes back to life. I have bone the firmware upgrade but it did not fix the problem. Some one on another page said to try holding the Volume down, it did not work. I am trying to set the SLEEP & powersaver to 120 minutes. It lasted 3 minutes then went down. 

Anyone have any ideas?