I have a Sony vaio model SVE151E11M and it won't boot. When turned on the LEDS turn on but nothing appears on screen. I have tried removing the CMOS battery, Reconnecting the screen cable, Using an external monitor (VGA and HDMI), Putting an SSD with windows 8.1 installed, reseating and cleaning the RAM and using a light on the screen to see if the backlight doesn't work. Nothing. Any suggestions to fix the laptop please.