That’s what I did!
I’ve cleaned the fan and grills (?), removed all the broken off/loose parts that accumulated over the years, but they weren’t the cause. Gotta say, it’s quite the sturdy machine. Several times it hit concrete already from about 1.2m height, but for some reason it did not actually immediately start to drrrrrrrrrrrrrr after that. It started around a week after the last fall. Or hit, actually. Falling does nothing, hitting the ground is the problem.
I’ve cleaned the fan, checked if a wing might be broken and put it back in.
That didn’t help. It’s not the fan itself.
I’ve opened it up again, pinpointed the source of the noise and screwed the screws around that place in tightly. That didn’t help either. It got a little less noisy, but the drrrrrrrrrr remains. I will have to open it up again, check from all sides, but I doubt I’ve not covered everything already. Next step is using Playdoh or something.
The other option to make it stop is throwing it against a wall. I’ve already considered that. Absolutely effective solution, it won’t make a single ■■■■■■■ noise anymore after that and it will be an absolutely satisfying thing to do.