Screen problems awaking from sleep

Hello,

I just replaced the LCD screen following your guide. The screen and isight camera worked fine. I also connected the computer to an external display and worked fine. The problem happens when I put the computer to sleep using any method (apple menu, power button, closing the lid). The computer wakes up but the screen is white wth some flickering and lines. In this state I can connect it to an external display, press function F7 and see the desktop in that monitor. So the computer is running but the screen is white!!! The only way to recover from this problem is by rebooting

Any ideas on how to fix this?

Thank you in advance

Pablo