How do I unlock a US Cellular GS3 to use on Straighttalk?

[Rose Hill1]

How to unlock a US Cellular GS3 to use on Straighttalk?

My daughter wants to use my Galaxy S3 on Straighttalk. I upgraded this phone to the S5 and was told the phone was unlocked for use wherever. I purchased the kit from Straighttalk to convert the phone over (new SIM card). Had it transferred but it doesn't work so had to transfer back to her old phone. Can someone tell me how to fix this?

 

[Rukbat]

Re: How to unlock a US Cellular GS3 to use on Straighttalk?

If the phone was using AT&T towers, get a Straight Talk AT&T SIM and it'll work. (You'll have to change the APN settings - they come with the SIM.) The phone was locked to AT&T and it "thinks" it's still on AT&T towers.

If it used US Cellular's own towers, the phone will ask you for the unlock code when you put in the ST SIM. Look on eBay for unlocking services. You give them the IMEI of the phone (it's on a label under the battery - it's usually labeled Dec:, the decimal number. There's also a Hex: number - same value in base 16 notation.) and some money and they give you the unlock code for that handset. (It's different for every S3.)

If the phone connected to the network (you could get/make phone calls) but not data or internet, that's simply the APN. You must use ST's APN, it won't work with US Cellular's APN (or even AT&T's APN, if it's on AT&T towers).