Power, but No Video (Computer begins to power up, the fans and hard drive spin, the Caps Lock key lights up when pressed, but there is no startup chime or video.)
Note: Examine the display carefully. An image may be barely present on the screen, but with no backlight clearly illuminating the image. In this case, the system is working properly except for the backlight.
Reset the SMC (power manager) as described in “1. Resetting the System Management Controller (SMC)” under “Troubleshooting Tips and Tricks” in the previous section.
Try connecting an external display to check for intact video signal.' If external video appears, 2. check the system for any pending software or firmware updates and update accordingly.
Verify that the LVDS cable connection is properly seated to its connector on the logic board 3. and that the cables are not damaged.
Replace the display assembly.4.
Check all cable and flex connections to the logic board. Try restarting.5.
Replace the logic board.