Hi,
after formating the device the info where wich file is located is wiped. At that point chances were good if you tried then to recover the files.
But you installed a new firmware. Maybe this wiped some files forever. But you can still try to recover some files, i would choose a program called testdisk.
But you should know what you are doing. There is a chance that this damages your device. Data recovery is not a simple task.
I’m sorry for you. :cry:
hth
