O2 sim card

[JamesJRM]

I have a old phone with o2 SIM card in. J230i Sony Ericsson.

o2 gave me a unlocking code and how to use it . However when I put another SIM card in the phone it comes up insert correct sim. It will only work when I put the O2 sim back in . Can anyone advice what the problem could be. 
many thanks 

jim

[madasaf1sh]

@JamesJRM 

That really is a classic phone from 2005... 

It could be the sim card as since 2005 there have been different iterations and capacity increases which make the older phones not kick in, I have the same problem on a old Nokia Banana Phone...

[JamesJRM]

Thanks for you responses . Will a O2 shop be able to help or is it not fixable

JR

[jonsie]

Best option is to call in the O2 store and get a replacement sim

It's FOC and they will swap the number over for you

[MI5 · Accepted solution]

@JamesJRM 

1. Insert an unaccepted simcard and start Sony ericsson J230i
2. Press the following buttons left, * (STAR), *(STAR), left. (use the directional button at the center of your J230i, make sure you press the buttons quickly or the hidden menu won't appear)
3. Hidden unlock menu should appear.
4. Enter the unlock received from O2
5. Sony ericsson J230i is now prepared to work in any network.

How to check Sony-Ericsson J230i code counter:

1. Turn on the phone whithout sim card
2. Lock screen
3. Press sequence: Menu, Back, Back, Menu, Back, Menu, Menu, Back
4. Select Service info
5. Select SimLock
6. Check where is X
7. If X is on NETWORK, SUBSET or PROVIDER and value is different than zero, you can unlock your phone.
8. If it is zero unlock by code is NOT available. The counter is blocked.

If the code counter shows all 0 it cannot be unlocked, because there are no tries left to unlock it.

https://sim-unlock.net/simlock/Sony-Ericsson/J230i/