there's an internal problem with your device

[Rp9]

1. screen goes black while outgoing and incoming cal.

2. call dosen't dissconnect after call.

3. i repaired my device with xperia companion , but my problem dosen't solve

4. video freezes many times while playing video

5. fone heats too much .

6. device dosen't reboot while pressing buttons  volume down+volume up+power button.

7. *#*#7378423#*#* by dialing these numbers device reseats but dosen't work well

[Lord_viridis]

Myself, I would contact Local support and see about getting the device looked at. It may need a repair.