Can using a SIM lock a unlocked phone? (Galaxy Nexus)

[jeff_pony]

Hi Guys,

Pulling my hair out here. For over two years now I have had a t-mobile contract, it came with a locked HTC Desire. Since the contract expired I have intended to move to a SIM only contract and buy my phones (I got burned by t-mobiles price hikes).

A few months back a friend of mine sold me his unlocked Samsung Galaxy Nexus when he upgraded phone. He had been using this phone with a 3 Mobile contract SIM. Once I got the phone, I dumped my HTC for the Nexus and installed my t-mob SIM. Everything worked first time and I have been using the phone for around two months without hitch.

I have now decided to get the SIM only contact sorted and have got 3 Mobile to send through a contract SIM. I have tried installing this SIM but no dice, the phone just reports that "no SIM installed". I have tried a orange PAYG SIM and that is not seen either. I have gone into a 3 Mobile shop and tried one of their SIM's, that also does not work. The 3 SIM does work on a old 3 Mobile phone that I have.

So everything points to the phone, although of course the t-mobile SIM is working without a hitch.

So my question is, could using my t-moblie SIM have somehow bound my phone to their network and if so, can I reverse this?

Cheers,

Jeff.

[n_K]

Never heard of that before and I highly doubt it. There are security modes (at least on old nokias anyway) that if you change the sim, you're asked for a code and if you don't get the new code right it will refuse to boot until the sim card it was set with is put back in.

[jeff_pony]

I don't get prompted for a pin, could it be that t-mobile specific settings get written into the Android OS somewhere?

I have read that there is a bug in Jelly Bean, that upon updating to this version of android your phone becomes locked to its current SIM. There is a galaxsim unlock app for routed phones that I have run from the android store, this reports that nothing is locked on my current phone. I then thought it might be settings on the phone OS, so I have reflashed the stock ROM to the phone.

Since owning a phone, I have never encountered something like this. Its bizarre!

[Soldiers33]

yes its possible but dont know how. once I unlocked an xperia arc on orange sent it to sony for repair came back locked again.

[Shadrack]

I don't get prompted for a pin, could it be that t-mobile specific settings get written into the Android OS somewhere?

I would think at most it would just mess with your ability to receive data (APN settings).

I have read that there is a bug in Jelly Bean, that upon updating to this version of android your phone becomes locked to its current SIM. There is a galaxsim unlock app for routed phones that I have run from the android store, this reports that nothing is locked on my current phone. I then thought it might be settings on the phone OS, so I have reflashed the stock ROM to the phone.

Since owning a phone, I have never encountered something like this. Its bizarre!

It is odd and if you get to the bottom of it please report back. Some of us who have unlocked phones would like to know what you find out.

[jeff_pony]

On my stumbles around the net this is one of the links I have found, although nothing generally describes my problem. At this point I am guessing what the issue might be:

http://forum.xda-dev...d.php?t=1954919 (Jellybean locks on update)

I also cannot add APN settings manually, the T-mobile sim populates these straight away where as the 3mobile does not :(

[jeff_pony]

Turns out that my sim reader is missing a connector. Not sure how the tmob sim has carried on working, but there you go. Will send phone in for repair, hopefully under warranty.