[Galaxy S II Q&A, Help & Troubleshooting] Gbobaz:
Here is how I solved the problem:

English:

0. Check the IMEI malfunction writing *#06# on the Phone's keyboard. It should open a little window sayin' "unknown" or something like that.

1. Download the package of the XXKH3 firmware; I used this link: http://www.meksone.com/come-riportare-in-vita-un-galaxy-s2-senza-imei/.

2. Follow the guide at this link: http://www.obit8.com/ripristino-cartella-efs-samsung-galaxy-s2/.

3. Before to execute the part named "Passo 2" of the guide (which unfortunately costs €32,47), flash the firmware XWLPF (download here: http://www.androidiani.com/forum/mo...are-i9100xwlpf-italia-4-0-3-26-05-2012-a.html) using Odin.

4. Root the Phone using from ricovery the zip file named "Root_Superuser_3.1.3_Busybox_1.20.2-Update1-signed.zip" at the bottom of the first post at the page http://xdaforums.com/showthread.php?p=28178105 ; doesn't need CWM.

5.Check on the box to find your IMEI code, or on the phone itself, under the battery. Write it somewhere and write the serial number too.

6. Execute "Passo 2" of the guide as it is explained in the video at the same page or at https://www.youtube.com/watch?v=vXmhLRPXokM.

7. Check that your IMEI is now back on the phone writing *#06#.

8. If now the phone still doesn't have signal, go to the system settings of your phone, then Security, Set Up Sim Card Lock and make "Lock Sim Card" without the cross. Now your phone should receive signal and you can again put the cross to block the phone with your pin number.

9.Other problems your phone should have are the missing rebooting menu and lockscreen even if enabled.

Using root explorer go to EFS folder, then IMEI and edit the file name "keystr" (if it doesn't exist, just create it) writing inside of it "ON" (just ON without ""), and set all the permissions (read, write, execute); open the file and check that ON is still written, if not write it again now that you have permissions.

Finished!!!!

Italian

0.Verificare l'anomalia del codice IMEI con *#06# che dovrebbe dare "unknown".

1.Scaricare il pacchetto firmware XXKH3 al sito*http://www.meksone.com/come-riportare-in-ita-un-galaxy-s2-senza-imei/.

2.Seguire la guida al sito*http://www.obit8.com/ripristino-cartella-efs-samsung-galaxy-s2/.

3.Prima di eseguire il "Passo 2" della guida, che prevede purtroppo una spesa di €32,47, passare tramite Odin al Firmware XWLPF (download qui*http://www.androidiani.com/forum/mo...re-i9100x.wlpf-italia-4-0-3-26-05-2012-a.html).

4.Effettuare il root con il file*Root_Superuser_3.1.3_Busybox_1.20.2-Update1-signed.zip*trovabile in fondo al primo post della pagina*http://xdaforums.com/showthread.php?p=28178105*senza hbisogno di installare CWM.

5.Sulla scatola del telefono o sotto la batteria dovrebbe esserci il codice seriale e l'IMEI. Segnarseli.

6.Eseguire il "Passo 2" come spiegato dal video*https://www.youtube.com/watch?v=vXmhLRPXokM.

7.Verificare con *#06# che l'IMEI ora sia il vostro.

8.Se il telefono non prende ancora, andare nelle impostazioni della sim e togliere la spunta da "blocca scheda sim".

9.Se il lockscreen non funziona e nemmeno il menu di spegnimento, tramite Root Explorer andare nella cartella EFS poi IMEI e modificare il file keystr (se non c'è, createlo) scrivendoci dentro "ON" (solo ON senza virgolette), controllare che resti scritto e settare tutti i permessi (read, write, execute).

10. Reimpostare il "blocco scheda sim" se voluto.

:D

Inviato dal mio GT-I9100 con Tapatalk 2