GSM phone from Ebay

[r***@gmail.com]

I really screwed up last week and purchased a GSM phone from Ebay. Big, big mistake. The phone is a new unlocked Samsung Galaxy S III GT-I9300 (Model # SGH-T999) with Android Version 4.1.1 ”Jelly Bean”. When it arrived, the phone had "T-Mobile" written on the back and all the apps seem to be from T-Mobile. It also states that the carrier is T-Mobile. The seller of this phone never reviled this information. However, it is a very nice phone.
Here is my problem. I am using H20 Mobile prepaid service which exclusively uses AT&T Mobile. I want to use this phone for AT&T service because they have the best reception in my local area. The T-Mobile reception is terrible here. While driving, sometimes the phone wants to connect to T-Mobile towers and indicates the service is not available. Also, the internet connection tries to connect through T-Mobile while on the road. The message says I don’t have an account.
My question: is there software available for download that I can reprogram this phone and use it with AT&T service?? I want to completely wipe T-Mobile off this phone. I am not sure what the next step should be but I have downloaded the latest ROM software "51c37773dec1b" V 13 called ”Jelly Bean”. I haven't installed it on my phone yet. Is it possible that this software upgrade might resolve the problem of this phone trying to connect to T Mobile towers???

[tlvp]

Post by r***@gmail.com
I really screwed up last week and purchased a GSM phone from Ebay. Big,
big mistake. The phone is a new unlocked Samsung Galaxy S III GT-I9300
(Model # SGH-T999) with Android Version 4.1.1 ”Jelly Bean”. When it
arrived, the phone had "T-Mobile" written on the back and all the apps
seem to be from T-Mobile. It also states that the carrier is T-Mobile.
The seller of this phone never reviled this information. However, it
is a very nice phone. Here is my problem. I am using H20 Mobile prepaid
service which exclusively uses AT&T Mobile. I want to use this phone
for AT&T service because they have the best reception in my local area.
The T-Mobile reception is terrible here. While driving, sometimes the
phone wants to connect to T-Mobile towers and indicates the service is
not available. Also, the internet connection tries to connect through
T-Mobile while on the road. The message says I don’t have an account.
My question: is there software available for download that I can
reprogram this phone and use it with AT&T service?? I want to
completely wipe T-Mobile off this phone. I am not sure what the next
step should be but I have downloaded the latest ROM software
"51c37773dec1b" V 13 called ”Jelly Bean”. I haven't installed it on
my phone yet. Is it possible that this software upgrade might resolve
the problem of this phone trying to connect to T Mobile towers???

I'm a bit confused. Is the handset in question still SIM-locked, and usable
with T-Mobile SIMs only? Or is it SIM-unlocked, and accepting your H2O SIM
without complaint?

If the former, you need to get T-Mobile to issue you a SUK (SIM-subsidy
Unlock Code), and instructions for its use, before you'll get anywhere.

If the latter, does your service provider have any roaming agreement with
T-Mo? If not, it may well be the case that the T-Mo firmware on the phone
is forcing it to try to connect to any T-Mo towers it detects, even though
doing so would be fruitless if your H2O provider has no roaming agreement.

If so, on the other hand, and the T-Mo signal is too weak, you're in
trouble unless you can somehow reflash the phone with an OS that doesn't
favor T-Mo even when an AT&T tower's signal is much stronger.

HTH. Cheers, -- tlvp
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Avant de repondre, jeter la poubelle, SVP.