Xperia V doesn't boot anymore.

[Dema]

2 days ago I charged my phone, but then suddenly it stopped charging.

I was still able to use the phone, turn it off and boot again, but it still wouldn't charge.

I also tried reinserting the battery.

At this point it looks like the battery is charged, I get a green led when connecting it to the power, before it was red.

But I still can't boot.  When I connect it to the power it tries to start automatically and the led goes off.  The Sony logo appears on the screen, but after a few seconds it dissappears again and the phone is turned off.  This process continues the whole time while it's connect to the power.

I already tried to use Sony update Service and PC companion, but I'm unable to connect my phone.  It just doesn't start.

I also tried resetting, by holding the volume and power btns, doesn't do anything.

Is there anyone who has had the same issue or knows what this could be?

[Dema]

For some reason the led is now red again.

So when unpowered, and I try to turn on the phone, the led blinks red.  Like the battery isn't charged.

[Alexander1]

I suggest that you keep charging your phone for a couple of hours. You could also try to charge the phone using another charger. 

If the phone still doesn't start after a few hours, try to remove SIM card and SD card from the phone and just put back the battery. Try to start it again. 

[Dema]

I  tried charging it for a few hours, but it doesn't seem to charge, since the phone tries to start the whole time.

I removed the SIM and SD card, but it still doesn't start.

[Alexander1]

If you have tried with Update Service with no success I suggest that you have the phone examined by an authorized  service center. Please contact your local support team for more information: 

http://www.sonymobile.com/global-en/support/contact-us/