Yes you can try by disconnecting the battery for some minutes. If that doesn't work then maybe there is some corruption in non-volatile memory. Clearly there is more going on than just a faulty software file, a successful re-formatting clears all files from the visible file system as you are aware.

Do you have Mass Storage Mode still available? If so, what is showing when you connect to the computer? Also did you use RMPrepUSB for formatting?