First, try a rest by holding the power switch in the uppermost position for 20-30 seconds. This normally is enough, but some have said up to a minute hold was needed to completely reset the device.
If it still doesn’t work, you should probably check out some of the existing threads on the subject. Some have had luck by formatting the player, some by re-installing the firmware, and some no luck at all. The v2 Fuzes seem to be more prone to this phenomenon then their predecessor (the v1 model) and there is no clear known reason or bullet-proof fix for it.
