Hi chaps, i had this Sony SVE1511C5E for repair with a very strange behavior.
If you press the Power button it did start but does not show any picture on the LCD, if RAM is been changed it immediately stars looping like On for a 1sec then OFF for 5sec then On again and Off ....
Problem is solved by reprogramming the BIOS chip W25q64 -8MB with the provided BIOS DUMP from another machine!

Hope this info will help to any one struggling with the same issue
Best Regards

P.S.
Board is DA0HK5MB6F0 MBX-269 REV-F
Hub is HM76 Intel SLJ8E