You experience either of these problems when using your Xbox 360 console:
Your screen remains blank or black when you start your console.
The circle of lights surrounding the console’s power button flashes red.
Often, this means the cable between the console and the TV or monitor is not connected correctly or is faulty. However, video settings or a hardware problem may also be to blame. See the troubleshooting information below for help.
To reset your display settings, follow these steps:
Make sure there’s no disc in the disc tray.
Turn off the console.
Turn on the console.
Note If you’re using an Xbox 360 Wireless Controller, make sure only one wireless controller is connected to the console, and then turn off and restart the console by using the Guide button on that controller.
As the console starts, press and hold Y while pulling the right trigger on the controller. The display settings are reset to the default settings, and then the console automatically restarts.
Xbox 360 E or Xbox 360 S console: To reset display setting on these console models, you can also just turn off the console and then hold the power button on the front of the console down for about 10 seconds. (The lights will flash several times.)
Solution 4: Check your TV setup
Basics to check:
Make sure that your TV is turned on.
Make sure the correct input is selected on your TV.
Remove any devices, such as a receiver, that are connected between the console and the TV.
If your TV has an eco/energy saving mode, turn that feature off in your TV’s video settings.