Question

Galaxy s10 5g Unlocked no 5g

  • 16 September 2020
  • 8 replies
  • 81 views

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I purchased an unlocked at&t s 10 5g Galaxy. I put my s7 sim card in the phone. It works- makes phone calls and connects to 4glte. I get no connection with 5G and Im in the Sacramento area - I have driven all throughtout the county- No 5G.

 

Tmobile Tech support on the phone said t mobile 5g wont work on this unlocked att s10 5g . Im getting conflicting answers.

 

Is there a setting to change? A different sim card?

 

Thank you for any help


8 replies

Userlevel 6
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With a SIM that old, you probably need a new SIM card.  

Edit:  Looking at GSM Arena, the only 5G band the AT&T device supports is N78.  T-Mobile uses 2, 5, 41, 66, 71 SA/NSA, so Support is correct.  

Userlevel 4
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The band-78 supported by this device is 3.5 GHz C-band, which is not currently used by T-Mobile.

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ug, what a bummer. Thank you

 

I take it the older SIM card I have in there woudl not change anything?

 

Please excuse me for being a clueless dolt when talking about bandwidths..

I appreciate all of your input.

The seller of the phone/ was brand new tells me they have seen it work and sent me this. Its a bit foreign to me.

 

Below are the 5g frequencies T-Mobile uses. this is taken right off their website.
5G

Frequencies that can provide 5G:
Band n71 (600 MHz)
Band n41 (2.5 GHz)
Band n260 (39 GHz)
Band n261 (28 GHz)
  The link below is to Samsung showing the specs of the phone. It picks up the N260 and N261 frequencies.

 

https://www.samsung.com/us/business/products/mobile/phones/galaxy-s/galaxy-s10-5g-256gb-at-t-sm-g977uzsaatt/

Userlevel 4
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  The link below is to Samsung showing the specs of the phone. It picks up the N260 and N261 frequencies.

 

 

The range of those bands is so short (a couple hundred feet) that they are only used in the centers of a few big cities.

It might help if you gave us the exact model number of the phone. That’s normally found under Settings → About Phone

Userlevel 6
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One thing to consider is visiting the XDA Forums for your device.  The newer Samsung devices from the US and Canada are all the same hardware for the most part and can be cross-flash able for their firmware.  You might be able to convert your device to the U1 firmware, which would be an improvement over the AT&T firmware and then convert from the U1 to the TMB U firmware if you want the full T-Mobile experience and potentially better 5G band compatibility. 

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Model number  SM-G977U

 

ugh..flashing U1 TMB U firmware is a bit past my learning curve. I have too many other hobbies to start screwing around with a couple hours of figuring out this stuff. Real bummer

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ok Im going for  new firmware. Guy at Mobile store said use Odin and email Samsung for latest Tmobile Firmware. Not sure if that is best route. I have spent a bit of time on XDA..but it was a dead end on Tmobile s10 5g firmware

Userlevel 6
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ODIN will allow you to convert to the U1 and then U.  I personally always recommend flashing to the U1 first to help debloat and debrand the device as well as making sure the conversion all went well.  Then you skip the setup, enable USB Debugging again in Developer Options, and flash to the TMB U.  Again though, the U1 firmware is fully compatible with T-Mobile so you don't need to flash to the TMB U unless you want better carrier aggregation, a bunch of T-Mobile bloat, and Video Calling. 

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