Won't boot up with red flashing light

I have the 4 Gb version of the xbox 360 slim and it doesn't seem to want to turn on. The TV doesn't show that it even boots up and when I press the power button and it starts green for a second then flashes red (11 times if that's of any importance) while the fan sounds really loud. I looked it up and it said that red flashing could mean ventilation but I air dusted everything with an air compressor and the USB ports seem to be fine so I don't think it's a USB short. Can anyone help please?