Lenovo Fan error again

Saturday my trusted old Lenovo x61s started emitting strange fan sounds again and like last time it started failing to boot up with the "Fan error" error message. Not saying which fan was at fault, though I suspect it's the usual second fan found on some x61s models. Last time only eight months ago I had to exchange both fans, let's see how it goes this time around. At least I found out that I could still boot by pressing ESC when the error message appears.