is it still covered by warranty? do you see anything on the screen for example if you place it under a lamp, do you see anything on the screen? that would mean the backlight is faulty.
you may have a faulty backlight or loose connector. If you got warranty that will cover the fix.
warranty and user guides
you can also try updateing the firmware of the device. sandisk website go over here
select your sansa fuse from the list, click find driver
on the new page select sansa firmware updater click continue
click skip registeration
download the firmware updater
install the updater
plug in the device when asked and follow on screen instructions.