One of the big-ass fans in my Mac Pro's case is making "funny" noises, I did vacuum it on the inside without putting too much effort into it, but it persists.
I can barely hear it during daytime or when the music is playing, but the noise is high-pitched and as it's in half-empty room, with all the reverberation it's very annoying. I hoped that it would just pass, but it didn't after three days — if anything, it only got worse. I don't want to disassemble the fucking thing 😩