iPad getting error 1602 while restore ipad2 fw

[tphilakone]

hi all
i have ipad2 3g firmware version 4.3.3 jailbroken
i would like to upgrade to ios 5.1.1

I can't restore the ipsw (version 5.1.1)
when i point the ipsw it take too long and i getting error message (error 1602 )

how to fix this problem ?
so please help me out ?

thank advance

 

[Dav1]

Do you have SHSH blobs for your device stored? Has your device been
Jail broken? If not then you are out of luck, you can't...