so i follow all the steps from aekhong, my 3760 came with FW 2.30 US pcb is 8:
i made 3.60 us boot bin + chinese 2.20 , followed steps one by one including rename dirs.
everything went fine, first symtom it worked was due when i connected USB nos asks for garmin mode or storage... nice..

then i quicly uploaded 3d map , shows on screen but no luck, even thougn now i can see and select which pois to display on screen... also nice..

one thing i noticed is that the redraw od the map in any view (top, 3d,) became slower, sluggish, jumping frames all around... did a master reset, same thing...

just went back to us 4.10 and the unit is ok again..

i do not know if something went wrong, today i will try on the same hardware:
us 4.10 boot bin, +syng 2.30 rest to see if i see the same result...

any comments are welcome...