PSA: Nokia Lumia 1520 on T-Mobile USA post-August 15, 2017 - How to receive calls

[maverickrohan]

I had to go through this and the first line of defense agents were useless.

T-Mobile updated their network on 15th August 2017, after this upgrade here is what happened.

• I could send and receive texts.
• Make calls
• LTE, 4G & Edge data works fine
• But Incoming calls stopped completely - They would only go to Voice Mail (This is dangerous if someone is trying to get in touch with you during an emergency)

Apparently when they did the upgrade, their configs considered the Lumia 1520 as a 2G device ... which means if your Network Selection is set to Automatic (which is the default), it fails to properly register the phone on their network.

The workaround is, you have to manually select your network as T-Mobile (2G) ... which means, you use the 2G network for calls and the manual T-Mobile APNs work for LTE data.

This worked for me but lets see how it does over the next few days.

Thanks & Kind Regards,

 

[PerfectReign]

That's wild. I don't have a SIM in my 1520 but will check.

Sent from mTalk on my 950xl

 

[maverickrohan]

UPDATE:

Manually connecting to the T-Mobile network was only a temporary fix, as soon as the phone connects to another tower or reconnects to the tower after losing network ... it goes back to its condition where you cannot receive incoming calls anymore ... I am supposed to do additional TS tomorrow with the T-Mobile technical agent, will update this thread.

 

[realwarder]

UPDATE:

Manually connecting to the T-Mobile network was only a temporary fix, as soon as the phone connects to another tower or reconnects to the tower after losing network ... it goes back to its condition where you cannot receive incoming calls anymore ... I am supposed to do additional TS tomorrow with the T-Mobile technical agent, will update this thread.

What happened?

 

[nate0]

@maverickrohan
Is your 1520 an RM-938?

 

[maverickrohan]

What happened?

It worked intermittently (80% calls would go to VM) but now I don't use it anymore ... I got the Essential Phone & iPhone 7 Plus 128GB as work phone .... also because my phone battery was acting weird ... at times the phone would go from 100% to 80% and straight to 0 and die in 10 minutes.

 

[maverickrohan]

@maverickrohan
Is your 1520 an RM-938?

It is the at&t variant, so RM-940.

One of the reasons the Lumia 1520 RM-940 sucked on T-Mobile is because it lacked 700 MHz band 12. I had terribad reception almost everywhere.

PS:
https://en.wikipedia.org/wiki/T-Mobile_US#Radio_frequency_spectrum_chart
https://en.wikipedia.org/wiki/Nokia_Lumia_1520#Model_variants

 

[nate0]

It is the at&t variant, so RM-940.

One of the reasons the Lumia 1520 RM-940 sucked on T-Mobile is because it lacked 700 MHz band 12. I had terribad reception almost everywhere.

PS:
https://en.wikipedia.org/wiki/T-Mobile_US#Radio_frequency_spectrum_chart
https://en.wikipedia.org/wiki/Nokia_Lumia_1520#Model_variants

I found a way to enable additional bands on the AT&T variant. Band 12 is among them. The only issue I found however is it gets stuck in 4G when a call comes in and won't fail over to LTE. I am on AT&T and was trying to enable HD voice on the 1520 but never got it to work. In the process found I could enable 5 or 6 additional LTE bands.

FYI: https://forums.windowscentral.com/showthread.php?t=275583&p=3701060&viewfull=1#post3701060

I used AT&T variant NVI files from other Lumia phones. In theory it might be possible to do the same with T-Mobile variant NVI files (i.e. Lumia 640 XL LTE) to enable yours to have the right settings. I have to find time to explain how to do it in a Guide thread, but have not found the time to sit down and do that.