Brother HL-4200CN Service Manual page 299

2.8.5 Low toner sensing ...................................................................................................VI-32
2.8.6 Transfer and cleaning..............................................................................................VI-33
2.8.7 ADC and environment sensing................................................................................VI-34
2.8.8 Monitoring................................................................................................................VI-35
2.9 Fusing and Transportation
2.9.1 Fusing and fuser heat control..................................................................................VI-36
2.9.2 Fuser drive control...................................................................................................VI-37
2.9.3 Fan control...............................................................................................................VI-38
2.9.4 Exit and invert transportation...................................................................................VI-39
2.9.5 Exit and invert mechanism ......................................................................................VI-40
2.9.6 Monitoring................................................................................................................VI-41