i believe you have infinitely complicated your problem by cross flashing a firmware 4xxx on to a drive with a 2xxx firmware.
this is a no no and renders the drive un usable.
to make matters worse you then soldered pins 45-47.
i do not know if it is possible to reflash using the correct 2xxxx firmware. but you can try.
if you dumped your original firmware into a file BEFORE you flashed the 4xxx that may be a better solution.
the only point i am not sure about is whehter you should un solder the connection first you attempt to reflash. if i were you i would try to unsolder the connection first. and then backtrack in the exact order you did things.
good luck, i think you'll need it.