Try opening up the case and replacing the LEDs underneath the Xbox button. The problem may be shorted LEDs.
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Try opening up the case and replacing the LEDs underneath the Xbox button. The problem may be [https://www.ifixit.com/Wiki/PowerA_ProEX_Xbox_360_Wired_Controller_Troubleshooting#Section_Xbox_Button_LEDS_Do_Not_Light_Up|shorted LEDs].