Brother HL-3450CN Service Manual page 210

4.3 Left Side of the Printer ........................................................................................................... 7-32
4.3.1 Video Controller PCB ...................................................................................................... 7-32
4.3.2 MCTL PWB ..................................................................................................................... 7-34
4.3.3 High-voltage power supply unit (High voltage unit 3) ...................................................... 7-35
4.3.4 Interlock switch (Rear) .................................................................................................... 7-36
4.3.5 Drum encoder sensor (PS4) ........................................................................................... 7-37
4.3.6 Fuser connector 3 ........................................................................................................... 7-37
4.3.7 Rear cover 3 (R).............................................................................................................. 7-38
4.3.8 Low-voltage power-supply unit (Power supply unit 3 (EC)(US)) ..................................... 7-38
4.3.9 Interlock switch (Front) (for front cover) .......................................................................... 7-40
4.3.10 Toner key sensor (TNK)................................................................................................ 7-41
4.3.11 Toner sensor (TTR)....................................................................................................... 7-41
4.4 Paper Exit Unit ....................................................................................................................... 7-42
4.4.1 Rear cover 3 (U).............................................................................................................. 7-42
4.4.2 Top cover (Paper exit unit 3) / Fuser fan (FUFAN) (Cooling fan (EX)) ........................... 7-42
4.4.3 Cleaning roller sensor (PS5) ........................................................................................... 7-44
4.4.4 Paper full sensor (PS6) ................................................................................................... 7-44
4.4.5 Paper exit sensor (PS2) .................................................................................................. 7-45
4.4.6 Discharger brush (Discharging brush 3) ......................................................................... 7-45
4.4.7 Paper exit roller 3 ............................................................................................................ 7-46
4.5 Front of the Printer ................................................................................................................. 7-47
4.5.1 Front outer cover (Front cover 3) .................................................................................... 7-47
4.5.2 Front cover unit 3 ............................................................................................................ 7-47
4.5.3 Laser unit (scanner motor inclusive) (Optical Unit 3) ...................................................... 7-49
4.6 Rear of the Printer.................................................................................................................. 7-50
4.6.1 Rear access cover (TR unit cover 3) / Transfer unit 3 .................................................... 7-50
4.6.2 Transfer roller 3 ............................................................................................................... 7-51
4.6.3 Register roller .................................................................................................................. 7-51
4.6.4 Paper size sensor 3 (PSU).............................................................................................. 7-52
4.6.5 Paper feeding roller / Separator pad (2).......................................................................... 7-52
4.6.6 Paper empty sensor (PS3) / OHP sensor 3 (OHP) ......................................................... 7-53
4.6.7 Paper feeding sensor (PS1) ............................................................................................ 7-54
4.7 Fusing Unit............................................................................................................................. 7-54
4.7.1 Oil pan unit 3 ................................................................................................................... 7-55
4.7.2 Oil pad ............................................................................................................................. 7-55
4.7.3 Fusing heater lamp (Fusing heater 3 (US)(EC)) ............................................................. 7-56
NOTE:
Parts names printed in light blue color are the parts names used in the HL-3450CN Parts Reference
List.
7-3
HL-3450CN SERVICE MANUAL