Переведи девайс в режим модема, достучись до модема через гипертерминал и пробуй это:

ZTE AT-commands
disable/enable flashdrive
AT+ZCDRUN=8 enable
AT+ZCDRUN=9 disable

stay online
AT+ZOPRT=5

check net-/SIMlock
AT+ZSEC?
answer: <SEC_STATUE>,<SEC_ITEMS>
< SEC_STATUE >:
0 Initializing the encryption (Insignificant SEC_ITEMS)
1 Network Lock error. (Insignificant SEC_ITEMS)
2 Network Locked
3 Unlocked or correct MCC/MNC

<SEC_ITEMS>:
0 No action
1 Network lock
2 (U)SIM card lock
3 Network Lock and (U)SIM card Lock

Unlock
+ZNCK="unlock-code"
+ZNCK?
Unlock residual time 0-5

Удачи:)