My Z3100 44" started making noises today, a familiar sound of a dirty fan you might expect to hear in a computer case.
I have a copy of the 300+ page service manual - it's a bit of a daunting task to open up the printer, I'm curious if anyone else has had this problem and fixed it permanently.
I temporarily solved the problem by tapping on the power supply box and the fan stopped making the wrrrr wrrrr wrrrr vacuum-cleaner sound, thankfully, because it was pretty loud and annoying.