Laptop wont turn on after putting it back together

[Crazysealions]

I took apart my Lenovo t400 to clean it out, I double checked and everything really looks fine and like its plugged in fine like normal, I plug the laptop in and I get the lights on the bottom of the screen that show that its plugged into the wall and the other light that says its charging the battery, Nothing at all happens when I push the power button on the keyboard, I ensured the keyboard is properly plugged in, I reseated the CPU, reseated the ram, Any ideas?

Thanks in advance

 

[Ubrales]

Make sure that the display connector is properly mated and the retainers at the ends are engaged. (This was the issue when my display would not turn ON - ok now).

 

[Pat Flynn]

Also check that the trim panel containing the power button has all of its ribbon/cable connectors connected. It sounds like the power button isn't actually attached.