ISW13HT failed jumping to diag

i was unlocking ISW13HT i have done unlock some pieces with xtc but
some other pieces are getting stuck for booting in special unlock menu after jumping to diag phone screen freeze blank it wasn't booting in special menu
i have checked my other unlocked isw13ht they are booting with the same hboot version but some pieces are getting stuck after jumping to diag
how can i figure out this prob