Aporte original por: David Iwanicki ,
"The screen is completly black no chime and the power led fade in and out." This is an indication the unit is 'sleeping'. Check the area around the sleep led - something might be triggering the sleep sensor inadvertently. On your model, it is part of the ribbon cable connecting the hard drive to the logic board - you might also want to check it for damage, debris, and proper routing.