mobile

Sony has just recently announced a SIM-Lock Free model for the Japanese market called Xperia J1 Compact (D5788), which is based on Docomo Xperia Z1 Compact (SO-02F). I'm not sure of the exact differences between the two in terms of hardware, but I have read that the front facing camera is different and the new J1 Compact does not support one-seg TV. Apart from that, the specs regarding CPU, RAM, GPU, etc. appears to be the same.

I was using my SO-02F with MVNO SIM (IIJMio - using Docomo backbone), and I was quite happy with it, but I still had lots of Docomo bloatware that I couldn't get rid of, plus, I had to root to get A-GPS working properly and use adb to get tethering to work.

Since I wasn't worried about losing the one-seg TV functionality, I decided to transplant the D5788 ROM and see what happens.

Although the D5788 has not been officially released for sale yet (April 20th is the due date), I found that I can download the firmware via Xperifirm V4.3. I then proceeded to burn the ROM via flashtool, Sony Mobile Flasher by Androxyde V0.9.18.5.

I will not be explaining the procedure in detail, as there are many tutorials in these forums that do. There are no magical settings or tricks that you need to be aware of.

In the short time that I have tested the device, everything appears to work normally. I was most concerned about the osaifu-ketai (felica) functionality, but it appears to be working fine. Both the front and back cameras are also working. No more Docomo bloatware but there are some Sony ones, but I can live with those as they are not as intrusive. Finally, the A-GPS and tethering works without going through the hoops.

If you own an SO-02F or SO-04F and using an MVNO SIM, then I would highly recommend you try this mod. If you don't like it, you can always flash back to stock. However, all the usual warnings apply and you do this at your own risk. THERE IS ALWAYS A RISK THAT YOU MAY BRICK YOUR DEVICE.