My old Xbox 360 went from a jet engine to library quiet in about two hours
I finally got around to opening up my launch model 360 that's been sitting in the closet for years. The fan noise was so loud you could hear it over the game audio. I took it apart, cleaned out a huge dust bunny the size of a quarter from the heatsink, and replaced the old thermal paste with some fresh Arctic MX-4 I had left over from a PC build. The difference is night and day. It's been running for a week now and I can barely hear it. Has anyone else had success with just a deep clean fixing older console noise, or is a fan replacement usually the next step?