Does Updating Unlocked AT&T Lumia 1520 to 8.1 Relock it?

Priceless Luigi

New member
Jul 23, 2014
11
0
0
Visit site
I bought an unlocked AT&T Lumia 1520 from Swappa about 2 weeks ago. I plan on using this phone for Tmobile. I used a friend's nano sim card to checked to see if it was unlocked, and it worked. Now that I have updated the phone to 8.1, would my phone be locked again?

I used the phone app to type in ##7820# to check, and it is giving me a picture of a lock and a sim card, asking me to type in the unlocked code.

UPDATE:
I switched from AT&T to T-mobile yesterday and received the unlock code for the phone from AT&T the day before. I tossed in the SIM card and found out that it is still unlocked. I also phoned ##7820# and still saw the lock and SIM icon. So the icon is a bad method to check if a phone is unlocked. Thanks everyone for their input about the situation. :smile:
 
Last edited:

MDK22

New member
Oct 17, 2013
1,375
0
0
Visit site
I think you got your answer, it's LOCKED - you have to re-enter the unlock code. If it was factory unlocked (never carrier locked) it would not require this.

I posted about this, yesterday.
 

MDK22

New member
Oct 17, 2013
1,375
0
0
Visit site
Thank you for the help. Man, didn't expect the phone to be relocked. Do you know ways to unlock it?
You need the unlock code from the carrier (AT&T).
Either go to the Online Unlock portal (under OLAM), but you have to be a current (or recent) customer.
Alternatively, call AT&T Customer Service (611) & talk to a CSR about your issue.

Possibly, Swappa can retrieve the unlock code from the seller.

There is also an unlock site on eBay (from Spain) which claims to unlock your Lumia 1520, though I can't recommend it.
 

Priceless Luigi

New member
Jul 23, 2014
11
0
0
Visit site
Thank you for the reply. I'm have contacted the seller on Swappa, so hopefully they respond soon. Also I'm a current AT&T customer under a family account with 3 basic phones and 1 smartphone, which was an iPhone. Do you think that AT&T would unlock my device? I looked over the Online Unlock Portal eligibility, and it seem that it could work. Sorry for asking all these questions all of a sudden.
 

MDK22

New member
Oct 17, 2013
1,375
0
0
Visit site
Thank you for the reply. I'm have contacted the seller on Swappa, so hopefully they respond soon. Also I'm a current AT&T customer under a family account with 3 basic phones and 1 smartphone, which was an iPhone. Do you think that AT&T would unlock my device? I looked over the Online Unlock Portal eligibility, and it seem that it could work. Sorry for asking all these questions all of a sudden.

YES, they will, as long as the device is NOT under subsidy (the seller's)
 

jdandison

New member
Apr 26, 2012
94
0
0
Visit site
I downgraded my 1520.1 to 8.0 to update to Cyan. The ATT lock certainly didn't come back. Sounds like someone sold you a locked phone.
 

pankaj981

New member
Jul 10, 2012
6,131
0
0
Visit site
I downgraded my 1520.1 to 8.0 to update to Cyan. The ATT lock certainly didn't come back. Sounds like someone sold you a locked phone.


Well the OP mentioned that a T-Mobile nano SIM worked before so looks like the device is unlocked. Unless the OP didn't test it correctly before
 

MDK22

New member
Oct 17, 2013
1,375
0
0
Visit site
I bought an AT&T sim locked phone (Lumia 1520.2 RM-940), requested the unlock code from AT&T and (carrier / sim) unlocked the phone (not to be confused with factory unlocked - or NEVER carrier locked).

After downgrading to WinPhone 8.0 from Dev Preview 8.1, then installing the AT&T Cyan / 8.1 update ...
I checked the phone (##7820#) and found it was carrier locked, again. I entered the unlock code (I saved the email) and voila, unlocked, again. Just the facts, so someone else doesn't get stuck.
 

MDK22

New member
Oct 17, 2013
1,375
0
0
Visit site
I downgraded my 1520.1 to 8.0 to update to Cyan. The ATT lock certainly didn't come back. Sounds like someone sold you a locked phone.
Hmmmmmm, the Lumia 1520.1 you reference, is NOT an AT&T phone - it's a factory unlocked phone - a NEVER carrier locked phone. The AT&T variant is the Lumia 1520.2 (RM-940), guessing you have an RM-937 ?

When you take a carrier / retail ROM, they send the carrier software, including sim / carrier LOCK. Remember, everything is reset - if you do a factory (Hard) reset after upgrading, you don't go back to the software the device is shipped with, you go back to the latest FULL software update - TRY IT !
 

jdandison

New member
Apr 26, 2012
94
0
0
Visit site
Interesting. I've had a t-mobile SIM in my phone for months, downgraded to 8.0, installed 8.1 cyan, and my phone has been fine. Tmo SIM working the whole time. Just dialed ##7820# and it shows as locked, but my sim is fine. OP, does your tmo service not work? If it does, it probably doesn't matter what the ##7820# screen shows.
 

jdandison

New member
Apr 26, 2012
94
0
0
Visit site
Hmmmmmm, the Lumia 1520.1 you reference, is NOT an AT&T phone - it's a factory unlocked phone - a NEVER carrier locked phone. The AT&T variant is the Lumia 1520.2 (RM-940), guessing you have an RM-937 ?

Correct, apologies, I have thr ATT variant.
 

MDK22

New member
Oct 17, 2013
1,375
0
0
Visit site
Interesting. I've had a t-mobile SIM in my phone for months, downgraded to 8.0, installed 8.1 cyan, and my phone has been fine. Tmo SIM working the whole time. Just dialed ##7820# and it shows as locked, but my sim is fine. OP, does your tmo service not work? If it does, it probably doesn't matter what the ##7820# screen shows.

Was the sim in the phone, when you took the update ?

That could be the difference, but as you said - interesting !

better safe, than sorry
 

Priceless Luigi

New member
Jul 23, 2014
11
0
0
Visit site
I got the phone when it was just windows phone 8. First thing i did with it is I factory restored it and then used a friend's Tmobile sim card and it worked. I can make calls, send and receive texts, browse the web, etc. Since then I assumed it was unlocked. Then I updated the phone to 8.1 when AT&T announced it earlier this week. Today I checked the ##7820# and it said it's still locked. Not too sure what is happening. U'm going to Tmobile this Friday to check if their sim card still works
 

sstiwari

New member
Jul 19, 2013
42
0
0
Visit site
I bought an unlocked AT&T Lumia 1520 from Swappa about 2 weeks ago. I plan on using this phone for Tmobile. I used a friend's nano sim card to checked to see if it was unlocked, and it worked. Now that I have updated the phone to 8.1, would my phone be locked again?

I used the phone app to type in ##7820# to check, and it is giving me a picture of a lock and a sim card, asking me to type in the unlocked code.

I also have an unlocked AT&T RM-940 in India. It also shows lock & sim on typing ##7820#, after cyan update.

However, tried four different Indian Sim-cards and there is no issue at all. The Phone remains unlocked. So do not worry about lock image. Actually insert another sim card and check network services. A Nokia phone once unlocked is always unlocked, even Nokia can not lock it again.

Cheers,
 

Priceless Luigi

New member
Jul 23, 2014
11
0
0
Visit site
That's what I assuming. I'm currently on AT&T at the moment, but will be going to T-mobile on Friday to switch. I have no access to a T-Mobile sim card at this moment.
 

Priceless Luigi

New member
Jul 23, 2014
11
0
0
Visit site
Well the OP mentioned that a T-Mobile nano SIM worked before so looks like the device is unlocked. Unless the OP didn't test it correctly before

I was able to make, and receive calls, send and receive texts, browse the web with LTE, and etc. In addition, the phone app said T-mobile on the live tile. Not to sure what is happening. I going to T-mobile on Friday to check it out.
 

Members online

No members online now.

Forum statistics

Threads
322,911
Messages
2,242,885
Members
428,005
Latest member
COME ON WIN ANDROID (ADI)