Why upgrade failed?
 

Dears, is there some one can help me resume my nokia 770 ?
A bad experience: when I update my 770 to Hack os 2007 ! it's work well, but when I flash back to SU-18_2006SE_3.2006.49-2_PR_F5_MR0_ARM.bin, my 770 can not work , screen has no icon, so I flashed to Hack os 2007 again, still no screen show here !