Your Xbox is overheating. Its a common issue. You can do as I did and strap some fans to the bottom and help cool it off. Eventually you will probably get a RROD (Red Ring Of Death). At that point you will need to send it in to Microsoft for repair.
I get no signal detected on my TV from my Xbox360, even after changing to a new cable and connecting...
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I get no signal detected on my TV from my Xbox360, even after changing to a new cable and connecting to three different TVs. Is this a common issue?