XBox360 turns on and immediately turns off

Well...

It might be a console problem...

if you have done full powercycling the console and tried a different outlet...

If PSU light is solid green and orange then PSU is fine...

The best course of action is to send it in for repair...

You can do so on myservice.xbox.com

I've had the same problem. Mine started a few weeks ago. Mine happened around the time of a bad lightning storm, and I had everything plugged into the surge protector, but was useless.

I try to do a hard reset and when I first try turning it on, nothing happens. Then after a few button pushes, I get the light on and it shuts off. Then after a few more, I even get the fan going and then it shuts off. Never get the Xbox screen.

I have also tried all the options and replaced the power cord because some mentioned the 7a cord that came with it originally wasn't enough power. Nothing. I am considering trying to replace the power supply or motherboard, but don't know if its worth spending
$60-80 for a part and then it not work, especially when the new system is out soon.

I was hoping there would be more people on these forums posting this issue, but doesn't seem that way.

My pleasure and hope to see you online and back up and running sooner than later.

Thank you for your help

If none of those steps worked I would recommend opening a warranty check and possible service repair. But first before doing so, try as another troubleshooting step moving the console to a different room/tv and use a new HDMI cable if available to see if
it responds as it almost sounds related to detection by television input but could also be motherboard related and need service. Here is the service link for you and hopefully they can further help if the changing tvs test doesn't help you.

https://support.xbox.com/help/hardware-network/warranty-service/getting-your-product-serviced