Will replacing stock fan ban my console?
If I replace the stock fan in my Xbox 360 with something quieter, would my console be flagged as 'modded' and hence ban my console, or live account?
Solution 1:
This may void your warranty (for repairs), but will not be detected as a 'mod'.
Mods are considered to be any action or item that circumvents the built-in security measures of the console.
Solution 2:
I have heard of this happening to some people. Apparently, the fan causes a greater (or perhaps fluctuating) voltage drop which the console detects and reports back to Microsoft. This can apparently earn you a ban, possibly because mods can cause the same sort of effect.
Instead of replacing your existing fan, can you use an externally powered or USB fan to blow extra air in? I can't remember if the 360's fan is temperature sensing but that might cause it to run slower.