Are priiloader or savemiifrii working? Or not? When you did the softmod guide, did you keep system menu 4.3 or downgrade to 4.1? I would leave it unpluged for a night, if your lucky it will come back on. I don't see anything that you did to cause this, just bad luck.
Also download this
Have a look at that nand backup you made with nandbincheck.
From the shell do
Post the output here, it may give some clue. Or not.Code:nandbincheck nand.bin -all -vvv