My 360 has been unplayable due to an issue with these symptoms: it reboots after 5-10 mins of playing.  Any game.  From disc or HD (hard drive) i.e. playing N+ with no disc in the drive.  The power button is not stuck.  I have reseated the HD.  I have tried alternate controllers.  I have removed the wireless NIC.  I have tried it in the vertical stance and the horizontal stance.  It has NO error codes (like the RROD).   I have tried alternate power supplies and I have tried copying my saved games to a memory card and loading them from that. 

Once it reboots it sticks on the logo screen for a few minutes and then reboots again to the dashboard and it says that the disc is unplayable.  Personally, I think the thing is freaking fried.

I have sent it in once to M-soft and they sent it back, to no avail.  Any one else having this issue?

i've never even heard of that problem before, that sucks though

You might want to try and plug it into a different power socket, that might be the problem. What I would do is force it to get the RROD. Overheat it, and then send it in, they may fix it then.

You should call up customer service.

never heard of issues like that, maybe you should call M$

My best advice is to pull up a comfortable chair and make the call to customer support. :(

Thanks for the advice - Y'all rock for responding!  I have called them multiple times and they keep suggesting things I have already tried.  I have actually sent it in for repair once - they sent it back still broken.  I have another repair scheduled but only to send in the hard drive, but it seems that the hard drive is not the problem.  I think the whole thing is jacked up.  I think that I may just have to take the advice and loose an hour of my life, repeat the same story, get the same advice and convice the tech on the phone to let me send the xbox in for a replacement.  Thanks again for replying - Dan