Q: my ipad 2  won't start after 8.4  it just show the apple logo booting  every 2 min

my ipad 2  was  working  excelent  with  8.3,  i put  it  to install 8.4 update  pluged to charger , it  downloaded  the update  and  after apply,  just show  the apple logo  booting  every 2 min  over and  over.

i tried  to recover,  it  show the usb wire  and  serial number in itunes,  the logo and  bar,  say   waiting for  the  ipad  and  return unknow error 9.

its  the same  in DFU mode.

tried  in 3 pc  with  3 originals  wires.   could  be  any solution  or    i had  an ipad  and  now  i have  a brick ?