11 months ago I bought a new Galaxy Dual Core (SM-G355H/DS). I soon took it to the US and bought a new sim card through Consumer Cellular - a popular choice for people who do not want to sign up for a long term contract and who already have a phone. Anyway, my phone never did activate and work. On a call to their support center they kept insisting that the phone was locked. No doubt true if sourced in the US. I don't see how that can be as I could use any Thai company sim in it with no problem. I'm about to return to the US for a few months and would really like to use this phone.

Does anyone know what the problem was?

I wonder if it's Region Locked?

Locked bootloader?

Otherwise, what GSM and 3G Bands does your PHONE support and Consumer Cellular (MVNO of AT&T, and T-Mobile in some locations)

From what I found, your SM-G355H/DS supports:

GSM (Voice/SMS/2G data) 850, 900, 1800, 1900

3G UMTS/HSPA+ (Internet Data) 900, 1900, 2100 (some sites list only 850, 2100)

LTE n/a

* SIM2 slot: 3G Data not supported

Consumer Cellular operates:

GSM 850, 1900

3G 850, 1900

LTE bands 17 and 4 (AT&T network only)

So the SIM should subscribe to the network at least for GSM Voice and SMS.

Thanks RichCor. You have confirmed with some real specs what I only guessed at.

Anyone know how to determine if it is region or bootloader locked? I still have a week here to get this sorted.

Asian phones are not region locked

http://www.gsmarena.com/samsung_on_region_lock_you_need_5_min_of_voice_calls-news-7184.php

I still have a week here to get this sorted.

When you were in the US trying SIMs, what message did the phone give you, if any? Did it subscribe to the network, or throw an error message?

It would not subscribe to the network.

It would not subscribe to the network.

from personal experience, when i had the S3, All S3 is region locked. If you bought your from the states, it'll only work in the states.

I had bought my s3 2-3yrs ago, took it to Thailand, put a thai sim, it didnt recognize the sim. Had to buy a new phone.

S3 and Note 3's are region locked.

S4 and above are are unlocked.

p.s. if your s3 is rooted, you can change the APN to a specific Thai Sim Tower.