Help ZTE Merit 990g Straight Talk - SIM network unlock PIN

[rjacobs1058]

Replacing the SIM card (Straight Talk -> T-Mobile).

Initial Message: SIM card invalid

Many thanks to all contributors in several forums for all of the education and contributions of time/talents/work of which I have gleaned measurable experience.

Action:
1) Got the NCK/NP Code but could not get a menu option to enter it.
2) Custom ROM (stock minus bloat).

Current Message: SIM network unlock PIN menu
Action:
1) Tried NCK/NP Code -- Not accepted and "attempt counter(10)" decremented.

Lock Screen Message: Phone is SIM service provider locked

Config Changes:
Rooted, sd-ext4, CWM 5.x, Custom ROM

Current Config:
Android Version: 2.3.4 (after ROM -- was 2.3.5)
Kernel Version: 2.6.35.7 (zte stock)
Build Number: "Custom ROM"

Summary:
1) Config changes produced a "Unlocking Menu" that requires a PIN which is apparently not the same as a NCK/NP code.

Questions:
1) Where is this offending App (ROM/Kernel)?
2) Where is this "unlock counter attempt" file?
3) Is there a maint code to bypass this menu?

 

[RBBrittain]

Which SIM did you use when you first got your Merit? If you started with the one that came with your phone, odds are it's permanently locked to ST; but if you initially used a 100% AT&T-compatible SIM (including ST/Net10 AT&T BYOP) it should be unlockable. (Same goes for Net10 Merits; that's why I used my existing Net10 AT&T BYOP SIM with my Net10 Merit.)

Also, some online unlocking resources suggest using an 8-digit NCK/NP code from their ZTE Blade calculator on Merits that won't unlock with the usual ZTE NCK/NP code.

Finally, even if it's unlocked you may not get more than 2G data unless T-Mobile is now using the 1900 band for 3G in your area. (IIRC that was supposed to have been done nationwide by now, but I'm not 100% sure if it's happened everywhere.)

 

[rjacobs1058]

Thanks for the reply. This phone was a throw away from one of my daughter's friend as a replacement for my lost Nokia ($19.95). It had a ST SIM inside. I just tried a AT&T SIM and got the same message as the T-Mobile .. "Phone is SIM service provider locked" as opposed to "SIM Card not provisioned" when inserting ST.

Tried all of the researched unlock codes/generators I could find, to no AVAIL (pun intended).

As you probably can tell, 2G is a grand leap for me! I refuse to pay $25 to unlock this phone via the so called "Unlock Client" and since this has been touted to work for some people, that means that it is possible. I don't mind hacking this phone as it provides me with a challenge. I am seeking some pointers to continue my journey. I guess the firmware is next.