Had an analog Ricoh that kept on calling me back for blank pages. If i get there the machine works fine. Went back about 4 times. The last time i decided to camp out there to see what happens. It was an outside room so i waited under a tree for the operator to call me if the problem occurs. i noticed her go in start the job and close the door on her way out. About a hour later she called me to have a look. On opening the door the smell of ozone overwhelmed me. And the copies was blank. Asked her to leave the room door open and the problem was gone.