2. To protect motors from rain (and tenants from 14-th floor from noise), house comittee built a small shed over them
3. They left some holes for pipes. From the point of rain they are OK
4. But the holes are quite right size for a pigeon.
5. And there are lots of these flying rats around, always looking for a quiet dry place.
6. Result - both motors are neck deep in pigeon crap. and yes - one of them already stopped working and took control board down with it.