Unlocked V20 on AT&T not working

[mia_xoxo]

I'm really at a loss right now. I'm trying to use my unlocked T-Mobile V20 with my husband's AT&T sim card but I can't seem to get data or the network to come through. Anyone have any suggestions that may help get the phone to work?

 

[anon(3732391)]

you have to go thru AT&T. They will issue you a new sim at no charge. If you intend on using it on the same line... as long as it's unlocked you'll be able to use any ONE device at a time by switching out the sim.
I use two different Blackberrys and a S8+ on the same line (same phone number) one device at a time

 

[mia_xoxo]

Thank you. I'll give that a try and see if it works.

 

[flyingkytez]

I'm really at a loss right now. I'm trying to use my unlocked T-Mobile V20 with my husband's AT&T sim card but I can't seem to get data or the network to come through. Anyone have any suggestions that may help get the phone to work?

You have to change the APN settings. Go look up the configuration online and add the AT&T APN configuration. I've used AT&T phones on the T-Mobile network and vice versa for years, they work fine.

 

[flyingkytez]

Thank you. I'll give that a try and see if it works.

If they convince you to buy a new phone, don't do it lol. The phone should be 100% compatible, as long as it's unlocked.

 

[natehoy]

I'm really at a loss right now. I'm trying to use my unlocked T-Mobile V20 with my husband's AT&T sim card but I can't seem to get data or the network to come through. Anyone have any suggestions that may help get the phone to work?

It looks like from a hardware perspective the T-Mo V20 is partly LTE compatible with AT&T and fully compatible on non-LTE bands, so you should be good to go hardware-wise (just maybe not on LTE).

Most of AT&T's LTE deployment is done in the 700MHz spectrum (bands 12, 14, 17, 29). They only use bands 2, 4, 5, and 30 as "additional" bands where they need extra capacity. Of those bands, the T-Mo V20 supports 2, 4, and 5. So LTE compatibility will be rare. Possible, especially in more congested areas where AT&T has been forced to add another band, but I wouldn't count on it.

Having said that, AT&T uses 850MHz (band 5) and 1900MHz (band 2) for 3G (up to HSPA+). The T-Mo V20 supports both of those bands. So you should at least be getting a 3G (GSM, EDGE, HSPA, HSPA+) signal on AT&T with your T-Mobile phone.

So APN and then swapping the SIM seem to be the next two logical steps.


The overlap between AT&T and T-Mobile bands is nowhere near 100%, sadly, especially in rural areas where neither carrier has been forced to deploy "expansion" frequencies to offer up more choices for signal. Here in Maine, of the 5 unlocked AT&T phones I own and tried on T-Mobile, only two (my Moto X 2014, and Samsung Note 4) has ONE LTE band in common with T-Mobile that happens to be used around here (Band 4) and UTMS compatibility is nonexistent with anything I've tried, even after enabling everything in the diagnostic service menus. Fortunately for you, using a T-Mo phone on AT&T is not quite as grim.

 

[mia_xoxo]

So apparently they said that there would be a delay on the service coming through (since he has a unified account with directv) and that he'd have to wait 24 to 48 hours for it to kick in. We waited and nothing happened. The lady at the AT&T store put her sim in and instantly got service so we have no clue as to why his isn't working properly. Clearly the professionals didn't either.

 

[flyingkytez]

It looks like from a hardware perspective the T-Mo V20 is partly LTE compatible with AT&T and fully compatible on non-LTE bands, so you should be good to go hardware-wise (just maybe not on LTE).

Most of AT&T's LTE deployment is done in the 700MHz spectrum (bands 12, 14, 17, 29). They only use bands 2, 4, 5, and 30 as "additional" bands where they need extra capacity. Of those bands, the T-Mo V20 supports 2, 4, and 5. So LTE compatibility will be rare. Possible, especially in more congested areas where AT&T has been forced to add another band, but I wouldn't count on it.

Having said that, AT&T uses 850MHz (band 5) and 1900MHz (band 2) for 3G (up to HSPA+). The T-Mo V20 supports both of those bands. So you should at least be getting a 3G (GSM, EDGE, HSPA, HSPA+) signal on AT&T with your T-Mobile phone.

So APN and then swapping the SIM seem to be the next two logical steps.


The overlap between AT&T and T-Mobile bands is nowhere near 100%, sadly, especially in rural areas where neither carrier has been forced to deploy "expansion" frequencies to offer up more choices for signal. Here in Maine, of the 5 unlocked AT&T phones I own and tried on T-Mobile, only two (my Moto X 2014, and Samsung Note 4) has ONE LTE band in common with T-Mobile that happens to be used around here (Band 4) and UTMS compatibility is nonexistent with anything I've tried, even after enabling everything in the diagnostic service menus. Fortunately for you, using a T-Mo phone on AT&T is not quite as grim.

You won't notice much of a difference. Been using AT&T phones on T-Mobile and LTE speeds are pretty much the same. Maybe small improvements every year.

 

[flyingkytez]

So apparently they said that there would be a delay on the service coming through (since he has a unified account with directv) and that he'd have to wait 24 to 48 hours for it to kick in. We waited and nothing happened. The lady at the AT&T store put her sim in and instantly got service so we have no clue as to why his isn't working properly. Clearly the professionals didn't either.

Okay so it might be your service or SIM card having problems. They should be able to give you a new SIM for free (hopefully). Try going to another AT&T store or call customer service instead.

 

[mia_xoxo]

Yup we did that as well. Switched out the SIM and still couldn't get it to work. We can try customer service again but they seemed to be just as confused.

 

[natehoy]

You won't notice much of a difference. Been using AT&T phones on T-Mobile and LTE speeds are pretty much the same. Maybe small improvements every year.

Around here T-Mobile has the speed and AT&T has the coverage (when we're talking GSM carriers - overall Verizon rules the roost here in terms of coverage but they know it and charge accordingly - LOL).

In any case, I was talking about phone compatibility. Bringing my AT&T Note 4 to T-Mobile (Mint, technically) turned out to be not optimal because AT&T didn't enable T-Mobile's 3G bands on their phones at the time. I ended up with EDGE or limited LTE coverage (only Band 4). When I did get LTE, the speeds were amazing compared to AT&T's around here - but about half the time I was on EDGE in my home area because there were only a couple of towers where T-Mo had implemented Band 4.

 

[natehoy]

Yup we did that as well. Switched out the SIM and still couldn't get it to work. We can try customer service again but they seemed to be just as confused.

Can you go into the About Device / Status menu and post a screenshot of the first bit of that? Ideally with WiFi off.

If they are present, please don't include the IMEI, phone number, or serial number, or anything identifying like that - you can black those out or just not include them in your screenshot. Those don't help anyone here with diagnosis and it's not the kind of info you want on public forums.

What I'm looking for specifically is whether you have service at all, and what network type you are on.

You can also download an app called SignalCheck Lite by Blue Line Computing and post a screenshot of that - it provides more detailed information about what you are connected to (signal strength, band, provider, etc).

 

[texn884]

im thinking about going to tmobile on their 55+ age account deal 2 lines for $60.00 and my Unlocked LG V20 US996 version