Hi Guys, I know i am quite a few years too late but I think i found the answer, and a good ol’ fashioned cleanup and smack won’t do the trick 100% of the time. I recently refurbished my old SP3 due to cracked screen and noisy fan when tilted. I had to open everything including replacing thermal paste. Upon investigation, 2 major causes aside from dust accumulation. (1) The fan’s Axle and Hub lost its lubrication! There’s a tiny gap between the axle and the brass hub and when you introduce a movement that would oscillate the fan to its axle, it rubs and creates a weird noise. It does not sound scraping against the wall because the axle is rubbing the hub without any lubrication. Solution: Add a lithium grease or RC car grease to the hub and axle. Not too much. Just enough to cover the whole mechanism. I wouldn’t recommend WD-40 as it is too thin. (1) If the sound seems like it is scraping something, it could be because of the corrosion of metals around the fan blades. The aluminum surface directly in front...