xperia u wont boot after

[showpa]

My xperia U is getting struck in boot up. The Sony logo is appering follwed by the xperia logo and it is struck there. It is not moving further. What could be the problem?

[Jake-SonyXperia]

Hi showpa,

Welcome to the community! Since you're new please be sure that you have checked out our Discussion guidelines.

Sorry to hear about this issue, I first suggest that you try a simulated battery pull.

Hold the Power Key and the Volume Up key for around 10 seconds, the device should vibrate three times. Once done simply try powering the device on as normal.

Let me know how you get on.

[showpa]

i tried but it did not vibrate at all. i tried to repair it by connecting it to a computer but it prompted windows cannot recognize the  device as there might be a problem in the device.