someone says:
I bought this item after we had RRoD on 2 XBOXes in our household, blamed on lack of circulation. After looking around at the various coolers we decided the following:
USB POWERED COOLERS
We did not want one of those as it posted in other reviews and on other sites that the extra strain on the units scarce power is cause for overheating itself. Secondly, most of the USD units only have enough power 5V or so (limited by the USB port), for 1 fan. Thirdly: most USB units take but do not add USB ports to your XBOX. Especially the one on the back is aesthetically the most important and therefore you'd not want to give it up if you not get an additional port back on that cooler.
AC IN POWER PORT COOLERS
The are plugged into the adpater AC IN on the back of the XBOX. I stayed away from these since they, over time, leave discoloration on the AC IN space and MS has been known to reject servicing XBOXes with that discoloration stating that unauthorized use of the XBOX AC IN was the cause. This discussed elsewhere on the web and happened to a friend of our sons as well. The good thing about these coolers is that they hae unlimited power so the fans can be strong. They al;so allow for the XBOXes to be used in horizontal mode. Final note: these apparently also cuase strain on the XBOX's limited power (the XBOX is HUNGRY!!! hence the heat).
SEPARATELY POWERED COOLERS
This is the category that this item falls in: it comes with its own adapter and power button so you do not have to use it when the XBOX is barely on and you can leave it on after the XBOX has been powered off to further reduce the heat.
Downside to some is that that this item needs its own power outlet but that is worth it to us for the fact that it can drive 6 large computer fans without piutting strain on the XBOX power source and innards.
It also does not take away any scare ports nor will it leave discoloration. I.e. it is invisible to MS in case something ever happens.
FINAL THOUGHTS
Some 'scientists' on here calim that they used all kinds of thermometers and methods and claim these coolers (all types) do nothing for the heat. The fact is that you can feel the housing cool down once you switch these on after your XBOX has been on for a while. It is logicale as well. Cooler air is forced in from the bottom and pushed the warner air out through the sides and top. I recommend this item for the pure piece of mind that you have done the best you can for ventilation and that you have leiminated one more possible source of RRoD.
PS: this item will only allow vertical use of the XBOX 360. Make sure you have enough space. And also, this does not mean you can cram your XBOX in a closed off poorly ventilated cabinet as the heat will start recycling and feeding warmer air in. Ventilate your XBOX!
