PuXiongfei

Flash most earlier C5 ultra single sim firmware. If that will not help - your phone needs to be customized in Sony factory, because Sony Service Centres does not support prototype phones. Ergo - your phone can't be fixed at all.

thank you for your reply,Jurij.

I have tried flash firmware and simlock.ta file But it didn't help..

so I think I can find a prototype C5 single SIM TA FILE,use the "000007DA" area to flash my phone,it will repair SIM LOCK issue..

@Jurij HI~is any solution for C6902/L39h dead boot?new version s1tool will support it? 

I send my phone to Xperia Care.waiting for good news.

thank for you reply.

I tried hold power button and volume up together over 5 min,no response.

power button,volume up and volume down together over 5 min,no response.

the phone only light up red led when i connect to wall charger or computer.but nothing can be found in windows device manager.  

thank for you reply.

no water damaged,no fallen,I charge the phone as usual in night,when i woke up,the phone is no response and no charge led.I have no idea what happend.