toner cartridge expiration 125 DC power distribution 46 delivery roller motion 147 developing process 52 diagrams assembly 158 timing 59 distribution of power 46 document sensor (PS801) 55 documents fall out of feeder tray 136 door open sensor (SW101) 55 dots on pages 127 on scanned images 132 draft mode 49 DRAM (dynamic random-access memory) 48 driver circuits 56 roller motion 147 dropouts in characters 131 drum rotation functional check 143 drum, photosensitive charging 52 cleaning process 51 troubleshooting 125 dynamic random-access memory (DRAM) 48 E ECP interface 48 ECU (engine controller unit) description 44 loads 44 edge of paper, not printing to 126 C4224-90962 189