I wanted to share my experience to help other technicians and staff of the forum.
the notebook and an emachine 520 with motherboard la-4431p.
the problem and to 'start the display is lit but there' was no picture just black and no activity of 'hard disk.
I reprogrammed the flash the bios with the 'last emachine bios v 1.06 and the notebook has resumed normal operation.

may be videochip or bios not from this motherboard?