Anyone got a link to the firmware to unroot to ? Tried everything and my phone just doesn't work as well rooted as when I got it out the box. Software doesn't work like samsung link and most of all signal is 1 bar everywhere in Southampton for me. One of the few 4G cities in the country. im sat next to my missus on her iPhone 5s on EE with full signal. Absolutely fuming with this handset now and just want it working properly again.