How to Stop Freezing on "Boot 4.0" Logo Screen When Powering Up?

Hello. I have the same problem, but worse… Happened 1 month ago. I had Rockbox installed over a year and everything was fine. 

Now, and suddenly, the player is completely dead. I have to plug it to a laptop and then do the power-center reset thing in order to start, BUT then just freezes to “Boot 4.0”… The laptop “sees” the device as a 30,6mb drive (4giga is the normal) but its useless. Says that needs to be formatted to work but when i try to do it “windows cannont complete the format”…

Any ideas? Tried every combination of the buttons. I dont care about backing up, just want my player to work.