[Q] tablet freeze/boot lock

I have B-Tab eith android 4.0 wifi only, when i turn on my tab, i just only see lock icon and time with black background freeze. I'll try run factory reset, the process success, but after restarting still freeze cannot login to the menu. I restart and connect the tab to pc, after boot i can login to menu and use the tab but when i'm looking for storage from system setting, I cannot enter the storage info. If i plug off the cable data from pc to tab, tablet will reset then freeze on lock icon.
Pls help me to solve the problem.
tks