My xbox360 controller wont turn on

SOURCE: Wireless controller flashing green light but wont detect xbox360?

Have you pressed the connect button on the controller and the unlabeled connect button on the console? The console's button is the small round button between the memory card slots and the power button. Press them both and they will search for each other then marry. Do this for every new wireless controller you buy as well.

SOURCE: xbox360 wil turn on if i press button, wont recognize controller

its possible the ir board what could be faulty, your best best is to try and get one from ebay or on the net and replace it and see if that cures the problem. to remove the ir board simply take off the case then get a t8 screwdriver and on the front of the console clip off the small plastic cover and there is 3 screws holding this to the casing. remove them and pull off the ir board and replace it. put the console back together then try it again

hope this helps
www.fixmyconsole.co.uk

SOURCE: Xbox360 Power source

there could be a possiable problem with the brick part of the power source

SOURCE: controller will turn on xbox360 but will not do

hold both the connection buttons on the consel and the controler untill it conectes. if it dosnt connect then your controller mit be damaged and cant remember the software for it. try to get a different controller to conect to it to see if it conects.

SOURCE: My xbox360 dosent show any lights on power button

This could be that your hdmi cable is not inserted correctly, make sure that it is pushed fully into the console and the tv.
let us know if this helped.