Unlocking a Samsung Galaxy S4 from 3 after reset

[David]

I (sensibly I thought at the time) did a factory reset on our old S4
before using it for other purposes.
I didn't want anything personal left on it.
I assume that this is what you should do if selling or otherwise passing
on an old phone.

The phone was unlocked, and had been for years.

However after the factory reset it seems to be locked to the 3 network
again.

We have put in a request for an unlock code to 3 and got back a "this is
difficult and could take 10 working days" response but nothing since.

Is there an easy (and safe) 3rd party way to unlock an S4?


Cheers


Dave R


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[Theo]

David <wib...@btinternet.com> wrote:
> I (sensibly I thought at the time) did a factory reset on our old S4
> before using it for other purposes.
> I didn't want anything personal left on it.
> I assume that this is what you should do if selling or otherwise passing
> on an old phone.
>
> The phone was unlocked, and had been for years.
>
> However after the factory reset it seems to be locked to the 3 network
> again.

That surprises me. A factory reset shouldn't affect the SIM lock.
Once SIM unlocked it should stay unlocked.

> We have put in a request for an unlock code to 3 and got back a "this is
> difficult and could take 10 working days" response but nothing since.
>
> Is there an easy (and safe) 3rd party way to unlock an S4?

Supposedly there's a method here:
https://www.technobezz.com/root-unlock-samsung-galaxy-s4/
which looks plausible (not one of those sites which pretend to be unlocking
instructions and are either 'call your carrier for an unlock code' or 'pay
$$$ to $dodgy_unlock_service').

You can also reflash it with generic firmware via a USB cable, which would
remove any Three-specific apps and settings.

Theo

[David]

Thanks.

I was surprised that after the factory reset the phone seemed to be locked
to 3 again.

I agree that it should remain unlocked, or how can you pass a phone on to
someone else?

However the phone seems to work with the 3 network but refuse with other
networks.

I queried the symptoms and was told that it was because the phone was
locked.

I know that the phone wasn't always locked because we have put local SIM
cards in it when abroad.

I've just tried my Tesco (on O2) SIM card and the phone reports:
"Invalid SIM card. Network locked SIM card inserted.".

Which is a confusing message because it is usually a phone which is locked
to a network, not a SIM card.

I originally tried with a Virgin SIM card whith a similar result.

I'm going to try a range of SIM cards and see which (if any) work.
It certainly works(ish) with the old 3 SIM card which was in it before we
got a new SIM card for the account to go into a new phone.

[David]

Additional:

When I try to unlock the screen it prompts for "SIM network unlock PIN"
which sounds more as if it is refusing to accept the SIM because the SIM
is locked. Which as far as I know it shouldn't be.

Anyway, I've just inserted a SIM card where I still have the documentation
to hand including a 4 digit PIN number which I assume is the SIM card PIN.
However when I enter it the phone doesn't accept it.

Online resources:

<https://canadaunlocking.com/sim-network-unlock-pin>

"3) The SIM network Unlock PIN, has nothing to do with the screen PIN or
SIM card PIN. It has to do with what network your phone was made for.
When you bought your phone from a certain network carrier, they placed a
PIN on the phone so that you can only use it with their Network. This is
usually what is refered to as Network Locked. Now to unlock your network
you need a Network Unlock Code. Here is where it gets a little
confusing. This network unlock code goes by many different names. And
some phones (Apple) do not have codes at all. In the case of Apple
products, the network is unlocked through iTunes (after making a request
through the carrier or through a 3rd party unlocker). The common names
for Network unlock codes are: Network Control Key, NCK, Sim Network
Unlock Pin, Network Unlock Code, Network Unlock PIN, Master Unlock Code,
SIM network PIN and many other variations of those words.

More specifically, a SIM Unlock allows the SIM slot of your phone to
accept another carrier's SIM card (either locally or internationally.)

Unfortunately all phones don't use the same terminology so that makes it
more confusing! A simple way to remember is that if the POP up message
has the word "NETWORK" anywhere in it, that means that is has to to with
unlocking your network. If the word "NETWORK" is not found in the
message, then your phone asking for the SIM pin or the Screen PIN. "

So this does seem to confirm that the phone is locked to the 3 network.

I've just finished another round of testing and the SIM card out of the
latest 3 phone (in a SIM carrier) works in the S4.


So it seems conclusively proven that the phone is once more locked to 3.

Now I have doubly confirmed this I will give them a ring.

[David]

On Thu, 15 Aug 2019 07:46:28 +0000, David wrote:

> I (sensibly I thought at the time) did a factory reset on our old S4
> before using it for other purposes.
> I didn't want anything personal left on it.
> I assume that this is what you should do if selling or otherwise passing
> on an old phone.
>
> The phone was unlocked, and had been for years.
>
> However after the factory reset it seems to be locked to the 3 network
> again.
>
> We have put in a request for an unlock code to 3 and got back a "this is
> difficult and could take 10 working days" response but nothing since.
>
> Is there an easy (and safe) 3rd party way to unlock an S4?

Phew!
Sorted.

Used the Live Chat service and got the codes.
As far as I can tell the handset was unlocked when we bought it new from 3
(unlike the previous S3 which had to be unlocked).

Who would have thought that a factory reset would have caused it to be
locked to the 3 network?

Anyway, working now and I have the codes for future use.

I did check DC Unlocker which has been useful in the past but they don't
unlock Samsung phones.