Default Problem starting and then white screen P6 ...

Hello, I have a P6 processor with MTK 6589. The issue is that when I turn starts the boot and loads the boot image android then get a boat shaped jelly beans falling android while charging the device and before leaving the home screen starts to dim the screen and the images disappear until the white screen stays black and around ... It's a very rare thing, because I think that if it would not screen or boot images. ..

You know it may be due ????

Thank you in advance ...