Why is my xbox restart on its own?

Hi Coolguy2407940! I hope you are well, delighted to be able to offer you my help!

I'm sorry that you are going through this problem, I already have experience with this type of inconvenience because the same thing happened to me at the time.

In my case it was an overheating problem, but the problem cannot be due to the same thing specifically, there are also several factors. The recommendation I give you is to restore the power supply with the following steps:

Turn off your Xbox.
Unplug the power cord from the back of the console, power brick, and electrical outlet.
Wait 10 to 15 seconds to give the power supply time to reset.
Plug the cable back into the wall and into the power brick, but don't plug it back into the console yet.

If this does not work you can take a look at the following link for more information, there on the page there are more than 3 Solutions for this problem:

https://www.asurion.com/connect/tech-tips/fix-xbox-keeps-restarting/

Note: This is a non-Microsoft website. The page appears to be providing accurate, safe information. Watch out for ads on the site that may advertise products frequently classified as a PUP (Potentially Unwanted Products). Thoroughly research any product advertised on the site before you decide to download and install it.

Best regards,
Daniel.

For some weird reason I will be in a game but at random times the tv goes blank but the Xbox 360 is still on. Does anybody have any ideas what the problem could be?

According to Microsoft Help & Support article, this problem could be due to a hard drive not being correctly connected. Otherwise it states to apply for a repair.

Source: http://support.microsoft.com/kb/911152

When I had this issue it was the fact that I turned display discovery on in the xbox system settings, check to see if you have that turned on, if you do, turn it off and the restarts should stop. My theory is that display discovery has a hiccup, and then
the xbox thinks the inputs changed, forcing a restart.

there are many things that can cause your Xbox to do this, your Hardrive being one or your daashboard has a corrupted file in it or it could the resualt of an E73 Error. you can try taking out your Hardrive and playing a few games on your console to see
if it does it again! if it does not then you rule its your HDD. if it does then try unplugging everything and pluging everything back in one by one making sure all connections are fitted properly Esp. your Power Brick! if that does not resolve the issue i
suggest contacting Xbox Customer support at 1-800-4MY-XBOX about a possible Hardware Failure!