Just did my first (successful) fix for XBOX 360 having a RROD problem

[Frag Maniac]

at most they can detect the fan speed.

Not sure we're talking about the same thing. I was under the impression the 360s had chassis intrusion sensors too, to detect hardware modding. Some of the mod videos I've seen for instance talk about making sure you screw back in all the black screws, or MS's security measures kick in.