My Ouya started over heating. When I inspected the board, the fan actually turns on initially at boot for a split second then stops... never turning back on.
I think it is a problem of the latest OTA update as I remember it used to turn on before.
What I did was soldered some wires to the power leads and just have the fan on 100% of the time whenever it has power. This is not a good way to do it, because the fans are on even if the power is off (but physically connected to the power cable). So now I have to unplug it every time I am done. There are better ways to solder the fan on, so it is only on when the system is turned on, but for me it was a test.
At the end of the day, I think my Ouya was damaged because now it randomly locks up with graphical fuzzies on the screen. Also the HDMI will only output video but no sound. I have to unplug the HDMI and reconnect for the sound to come through.
I have not figured out why the Ouya locks up randomly. Sometimes I can play for hours while other times it plays for 30min. I mostly retro game, so now I just make use of the quick-save function so I do not lose my progress.