Chapter 77-7401xx: When the time from the detection of ITB HP to the detection of the next HP is less than the specified time (884msec or less)02xx: When the time from the detection of ITB HP to the detection of the next HP is more than the specified time (939msec or more)03xx: ITB HP was not detected only once. ITB home position sensor A/B should have detected alternately, however, the same HP were continuously detected.7.10 Photosensitive Drum Cleaning7.10.1 Overview of Drum Cleaning Unit 0013-9072imagePRESS C1 P / imagePRESS C1 / imagePRESS C1+ (Printer) / imagePRESS C1+The drum cleaning unit is placed at the side of the photosensitive drum inside the process unit. It has the function of collecting the residual toner on the photosensitivedrum.This unit is composed of five parts. It cleans the photosensitive drum to be ready for the next print.The residual toner collected by the brush roller and the cleaning blade is scraped by the scraper on the brush roller, collected by the waste toner feed screw into thewaste toner case at the back of the machine.These driving loads are controlled by the DC controller and transmitted by turning ON ITB/drum motor (M2).The cleaning pre-conditioning LED turns on at the same time.F-7-95[1] Cleaning blade[2] Brush roller[3] Scraper[4] Waste toner feed screw[5] Drum cleaning pre-conditioning LED[6] Side driver PCB7.10.2 Drum Cleaning Unit Drive Control 0014-0006imagePRESS C1 P / imagePRESS C1 / imagePRESS C1+ (Printer) / imagePRESS C1+The drum cleaning unit has two parts for activating load.These driving loads are controlled by the DC controller, transmitted by turning ON ITB/drum moto[1][2][3][4] [5]DC-CONJ1173 J1167M2J3416-2 PRE_EXP_LED_ON[6]