HP 5100 Service Manual - Page 93

Paper feed system Figure 24. Paper path The paper in Tray 1 is detected by the Tray 1 paper sensor (PS401). The paper in Tray 2 is detected by the Tray 2 paper sensor (PS301). The size of the paper in Tray 2 and the presence of Tray 2 installed in the printer are detected by four switches (SW403, SW404, SW405, and SW406) on the paper-handling PCA. When the paper is fed from Tray 2, the Tray 2 pickup solenoid (SL306) and the feed roller clutch (CL406) turn on while the main motor (M1) is rotating. Then the Tray 2 pickup roller and the feed roller start rotating to feed a sheet of paper into the printer. When the paper is fed from Tray 1, the Tray 1 pickup solenoid (SL404) turns on while the main motor (M1) is rotating. Then the Tray 1 feed roller starts rotating to feed a sheet of paper into the printer. The paper passes through the registration roller paper sensor (PS403) and stops at the registration rollers to momentarily stop the leading edge as its skew is corrected. Then the registration clutch (CL405) turns on to restart paper feed. The dc controller PCA sends the top of page signal (/TOP) to the formatter PCA within a specified period of time after the top of page sensor (PS402) detects the leading edge of the paper. The formatter PCA sends the video signal (/VDO, VDO) within a specified period of time after it receives the /TOP signal to align the image's leading edge on the photosensitive drum with the leading edge of the paper already fed. The paper then passes through the transfer area, feed belt, fuser, and delivery unit and is output onto the rear output bin or the top output bin. There are three photointerrupters (PS402, PS403, and PS1306) in the paper path to detect paper jams. If the paper does not reach or pass through any of the sensors within the specified period of time, the microprocessor (CPU) on the dc controller PCA notifies the formatter of a paper jam. Q1860-90918 Chapter 5 Functional information 91