Keeps shutting down, no hard drive found

So just a few days ago I was watching Netflix and all of a sudden my xbox turns off, it's never done anything like this before. I turned it back on and it just kept turning itself off and back on. So I let it sit for a couple days. Then I tried it again
and it did the same thing, just kept rebooting itself. I also noticed that it wouldn't recognize my hard drive, it's the stock one that came with it. All of his happened suddenly all at once. So I bought a new power supply today thinking that's what the problem
was and the problem is still going on. I took out the hard drive reset the Xbox and put it back in to try if that worked (Xbox support said to try that) but that didn't fix either problem. Overseen posts about Xbox's doing these problems separately but never
together, wanted to see if anyone had any ideas as to what it could be. Thanks for the help

:)

 

Xbox 360 power supply

hi my xbox 360 keeps shutting down when im in the middle of a game and its annoying me i have bought a security key screw driver to open the power supply and cleaned the fan but it keeps on shutting down is there any where i could buy a replacement in new
zealand

 

Keeps shutting down

Try unplugging your xbox and then plugging it back in, or go to settings and reset your xbox with keeping games and apps.

 

Try another input/output connection cable. So if you have it connected via the cable that with your xbox (Red, White, Yellow) Try using an HDMI cable if your TV has HDMI connectios, or reverse of that if you are already using an HDMI cable.

Unreconized HDD could be that when you pulled it you never got it seated in all the way when putting it back in.

Other than that. I've no idea.

 

When the hard drive was out, did you try playing the 360? Sounds like a bad drive.