[HOWTO] / [GUIDE] SPH-L720 Domestic SIM Unlock T-Mobile:AT&T:metroPCS:Straighttalk

[NATHANNEZ1984]

i was able to get it up and running on ng2 and i've tested it with both att and tmobile sims. Feel free to pm if you encounter problems, because i had every single one .

Tips:
1. Start fresh. Factory reset before you begin if possible.
2. Root your device, install busybox and supersu before the mdc modem (just the modem, not the whole firmware package).
3. When you are in *#0011# menu in step 5 of the original post your phone will say "plz reboot" at a point. Reboot then. This fixes the red x no signal issue.
4. If you are seeing the invalid sim issues you missed or messed up the international sim unlock step. Try it again. You run the program while your phone is still on the debug menu that says pda. You might need to reinstall the original firmware and modem if you are still seeing no signal. Once you have a signal with the original sim try starting over.
5. You will not see the apn settings for other services (att, tmobile, etc.) if you have a sprint sim in the device. I recommend putting in your new sim from the beginning.

Thanks to all the ops and everyone for posting all their helpful messages. I'm not an expert, but i would like to help others avoid the issues i encountered.

hello sir. So ive followed everything from beginning to end and just cant just quite get it. I started with a stock sph-l720 ng2 build. Odin flash auto root. Flashed mdc modem. Int'l unlocked just fine. Set back to mtp+adb in diag. And then when i follow the rest of the steps i cant seem to get it. Steps 9 and 11 is where i get thrown off and someone else is saying dont do the build.prop lines. So now im just all mixed up. Please help im losing it. Been here all day trying to get it. Id appreciate it.

 

[Rich-Man]

Ok I've followed this completely but am having 1 issue:
The unlock works fine with a T-mobile(Full Service sim from my note 3) , I can text,call,mms(i guess only have 1 sim card but 2 phones) but for some reason data is not working at all. It shows bars in the top corner but no 4g,4glte,3g etc., next to the bars. I have though flashed NG2 back over MDC too.

When I first tried this I mistakenly skipped step 2, using the unlock tool and only did the ##3424# part, however when i finished the guide, it said invalid sim, but , only the data worked but no call text or anything else.

Thank You.

 

[iBowToAndroid]

Question though. Since I am still using 4.4.2 but with a different modem now ( L720vpuaMDC instead of the L720vpufNG2 ) will I be able to upgrade to say lollipop or use a custom rom and not worry about losing my unlock? Or just rooting the thing to begin with?

Once unlocked, you are so permanently unless you redo Sprint's OTA provisioning. You can flash a custom ROM or even Odin back to stock without losing the unlock.

After having my phone unlocked for over three months all of the sudden it's re-locked. WTF happened?

Very low chance of it relocking. I suppose an OTA *might* have changed something. Otherwise make sure your IMEI is still clean

One problem I have with it, is the incoming voice tends to be unclear at times. It will sound almost like the voice is underwater, if that makes sense.

Phone is running MDC baseband, with T-mobile 4.4.2 Stock ROM.

Also, another question. Can I upgrade the baseband again after the unlock is complete?

Thanks

Yes you can upgrade the baseband again, and in your case, that will likely solve your issue

Ok I've followed this completely but am having 1 issue:
The unlock works fine with a T-mobile(Full Service sim from my note 3) , I can text,call,mms(i guess only have 1 sim card but 2 phones) but for some reason data is not working at all. It shows bars in the top corner but no 4g,4glte,3g etc., next to the bars. I have though flashed NG2 back over MDC too.

You're likely missing the APN

 

[Rich-Man]

Once unlocked, you are so permanently unless you redo Sprint's OTA provisioning. You can flash a custom ROM or even Odin back to stock without losing the unlock.

Very low chance of it relocking. I suppose an OTA *might* have changed something. Otherwise make sure your IMEI is still clean

Yes you can upgrade the baseband again, and in your case, that will likely solve your issue

You're likely missing the APN

You are correct the apn is empty but how do I fix that? Do I have to manually put it in?or is something wrong because it's supposed to do it automatically...
Thanks.

 

[daniel4653]

You are correct the apn is empty but how do I fix that? Do I have to manually put it in?or is something wrong because it's supposed to do it automatically...
Thanks.

You have to manually enter the APNs. Sprint Stock ROMs do not automatically detect sim cards and apply APNs

 

[NATHANNEZ1984]

After the international unlock

I started with a stock ng2 sprint s4 bad esn metro sim card in. I flashed cf auto root, flashed the mdc modem, did the international unlock smoothly and after changed the setting back to mtp+adb in diag mode. I followed the rest of the of the steps and keep getting no where red x thats it. So i started the process all over. ##rtn# and then odin flashed stock ng2 rom and cf auto root & flash mdc modem and international unlocked again. Can some one please help with the play by play from here. Do i pull the battery out when it says manual reboot or reboot?? Do i have to do the build.prop lines?? Someone please give me a hand.

---------- Post added 1st December 2014 at 12:03 AM ---------- Previous post was 30th November 2014 at 11:58 PM ----------

SORRY TO BOTHER YOU BUT YOU SEEM VERY KNOWLEDGEABLE CAN YOU HELP ME OUT???
After the international unlock
I started with a stock ng2 sprint s4 bad esn metro sim card in. I flashed cf auto root, flashed the mdc modem, did the international unlock smoothly and after changed the setting back to mtp+adb in diag mode. I followed the rest of the of the steps and keep getting no where red x thats it. So i started the process all over. ##rtn# and then odin flashed stock ng2 rom and cf auto root & flash mdc modem and international unlocked again. Can some one please help with the play by play from here. Do i pull the battery out when it says manual reboot or reboot?? Do i have to do the build.prop lines?? Someone please give me a hand.

 

[ochoabuddy]

Upgraded to newest baseband. Also somehow in the upgrade the phone says "4G" in the top bar, and internet speed has picked up. Says UTMS in the status page, so im assuming its just running HSPA+. Still nowhere near as fast as LTE but not too bad for speed.

Once unlocked, you are so permanently unless you redo Sprint's OTA provisioning. You can flash a custom ROM or even Odin back to stock without losing the unlock.

Very low chance of it relocking. I suppose an OTA *might* have changed something. Otherwise make sure your IMEI is still clean

Yes you can upgrade the baseband again, and in your case, that will likely solve your issue

You're likely missing the APN

 

[daniel4653]

Upgraded to newest baseband. Also somehow in the upgrade the phone says "4G" in the top bar, and internet speed has picked up. Says UTMS in the status page, so im assuming its just running HSPA+. Still nowhere near as fast as LTE but not too bad for speed.

You will never get LTE on a sprint GS4 on a GSM network. ATT and T-Mobile use different bands.

 

[Rich-Man]

You have to manually enter the APNs. Sprint Stock ROMs do not automatically detect sim cards and apply APNs

You are the best, I needed to make this couple of dollarz!!!

 

[NATHANNEZ1984]

Help a newbie out

you will never get lte on a sprint gs4 on a gsm network. Att and t-mobile use different bands.

can you help me out a bit?? I cant get it to work after international unlock. I do all the steps as ordered but all i get is a red x. Im starting with a international unlocked sph-l720 ngk build mdc modem bad esn with cricket sim in. Any help????

 

[ecs87]

can you help me out a bit?? I cant get it to work after international unlock. I do all the steps as ordered but all i get is a red x. Im starting with a international unlocked sph-l720 ngk build mdc modem bad esn with cricket sim in. Any help????

Check if your IMEI is blacklisted.

Sent from my LGLS990 using XDA Free mobile app

 

[rpetrover]

can you help me out a bit?? I cant get it to work after international unlock. I do all the steps as ordered but all i get is a red x. Im starting with a international unlocked sph-l720 ngk build mdc modem bad esn with cricket sim in. Any help????

I was having the same problem... What I did was when I got to the band selection. I choose ONLY GSM ALL... Anytime I selected LTE ALL it would not pick up anything.. just red X. I am using an activated US AT&T sim... I am able only to get H+ data with it, cannot get LTE on AT&T at all... don't know what to I have to do to get that.

 

[ecs87]

I was having the same problem... What I did was when I got to the band selection. I choose ONLY GSM ALL... Anytime I selected LTE ALL it would not pick up anything.. just red X. I am using an activated US AT&T sim... I am able only to get H+ data with it, cannot get LTE on AT&T at all... don't know what to I have to do to get that.

As far as I know, it has to do with LTE bands. Sprint phones obviously don't use the same bands as GSM carriers, so it won't work. And I wouldn't recommend the "mod" to add bands to your device. Enough people have bricked their EFS and basebands from it (which isn't an issue as long as you're fluent in raw backups and restores of the EFS data partitions from adb).

Sent from my LGLS990 using XDA Free mobile app

 

[daniel4653]

I was having the same problem... What I did was when I got to the band selection. I choose ONLY GSM ALL... Anytime I selected LTE ALL it would not pick up anything.. just red X. I am using an activated US AT&T sim... I am able only to get H+ data with it, cannot get LTE on AT&T at all... don't know what to I have to do to get that.

Like ecs87 said above me. The phone doesn't support the bands for ATT LTE. You should do some research before unlocking a phone.

 

[rpetrove]

Like ecs87 said above me. The phone doesn't support the bands for ATT LTE. You should do some research before unlocking a phone.

Ok, Mr. Grumpy... I am perfectly fine with the way my phone is. I don't care whether it gets LTE or not. I was just helping the other guy out who couldn't get any bars at all. My phone is better now even with out the LTE than a phone that I can't use at all and is good for just a paperweight... so I will just surf on with my HSPA+ speed

 

[daniel4653]

Ok, Mr. Grumpy... I am perfectly fine with the way my phone is. I don't care whether it gets LTE or not. I was just helping the other guy out who couldn't get any bars at all. My phone is better now even with out the LTE than a phone that I can't use at all and is good for just a paperweight... so I will just surf on with my HSPA+ speed

Not grumpy. I just get straight to the point. I've been on ATTs network now for 3 month now with HSPA+. I've bene happier than I was with Sprints crappy 3G network.

 

[delease]

Yea this is a odd one. I got my phone from a family friend who moved from sprint to verizon. She gave me her L720. Well I have it unlocked ( i think ) as its working for domestic calls, texting, data, etc. Thing is I went to set up my voice mail and it dialed her number. Like she actually picked up on her new phone.

Even after a i reset the phone a few times and I am using my own sim from tmobile in the phone, the VM dials her number &...in the about device > status section...under "my phone number"...it has her number listed still. Greyed out too.

I am stumped.

 

[daniel4653]

Yea this is a odd one. I got my phone from a family friend who moved from sprint to verizon. She gave me her L720. Well I have it unlocked ( i think ) as its working for domestic calls, texting, data, etc. Thing is I went to set up my voice mail and it dialed her number. Like she actually picked up on her new phone.

Even after a i reset the phone a few times and I am using my own sim from tmobile in the phone, the VM dials her number &...in the about device > status section...under "my phone number"...it has her number listed still. Greyed out too.

I am stumped.

Go into he dialers settings and change the voicemail number to your own. So when you hold the 1 button on the dial pad it will call your number instead of your friends.

 

[delease]

Thanks a bunch. It worked. Now...about the other part of my question. Why is her number coming up in the about device > status > my phone number section?

 

[ecs87]

Thanks a bunch. It worked. Now...about the other part of my question. Why is her number coming up in the about device > status > my phone number section?

It's probably pulling it from the CDMA portion (out of a NV item). If you really are concerned about it you can put the phone into DIAG mode, send the SPC and 16 character password through a CDMA tool program and change the MDN to your number. Fwiw, leave it. That's too much work for something so minor.

Sent from my LGLS990 using XDA Free mobile app