Ricoh B121 Service Manual page 15

3.3.2 REAR LOWER COVER (TWO-TRAY MODELS ONLY)...................3-4
3.3.3 COPY TRAY .....................................................................................3-5
3.3.4 UPPER COVERS .............................................................................3-5
3.3.5 LEFT COVER ...................................................................................3-6
3.3.6 FRONT COVER................................................................................3-6
3.3.7 FRONT RIGHT COVER ...................................................................3-7
3.3.8 RIGHT REAR COVER......................................................................3-7
3.3.9 RIGHT DOOR (B121/B122)/DUPLEX UNIT (B123) .........................3-8
3.3.10 BY-PASS TRAY..............................................................................3-9
3.3.11 LEFT LOWER COVER (TWO-TRAY MODELS ONLY)................3-10
3.3.12 RIGHT LOWER COVER (TWO-TRAY MODELS ONLY) .............3-10
3.3.13 PLATEN COVER SENSOR..........................................................3-10
3.4 SCANNER UNIT......................................................................................3-11
3.4.1 EXPOSURE GLASS/DF EXPOSURE GLASS ...............................3-11
Exposure Glass ..................................................................................3-11
DF Exposure Glass.............................................................................3-11
3.4.2 LENS BLOCK .................................................................................3-12
3.4.3 LAMP STABILIZER BOARD AND EXPOSURE LAMP...................3-12
3.4.4 ORIGINAL WIDTH/LENGTH SENSOR ..........................................3-13
Sensor Positions .................................................................................3-13
3.4.5 SCANNER MOTOR........................................................................3-14
3.4.6 SCANNER HOME POSITION SENSOR ........................................3-14
3.4.7 ADJUSTING SCANNER POSITIONS ............................................3-15
Overview.............................................................................................3-15
Adjusting the First Scanner Contact Points.........................................3-16
Adjusting the Second Scanner Contact Points ...................................3-17
3.5 LASER UNIT ...........................................................................................3-18
3.5.1 LOCATION OF CAUTION DECAL .................................................3-18
3.5.2 TONER SHIELD GLASS ................................................................3-19
3.5.3 LASER UNIT ..................................................................................3-19
3.5.4 LD UNIT..........................................................................................3-20
3.5.5 POLYGONAL MIRROR MOTOR....................................................3-20
3.5.6 LASER UNIT ALIGNMENT ADJUSTMENT....................................3-21
3.6 PCU SECTION ........................................................................................3-22
3.6.1 PCU ................................................................................................3-22
3.6.2 PICK-OFF PAWLS AND TONER DENSITY SENSOR...................3-22
3.6.3 OPC DRUM ....................................................................................3-23
3.6.4 CHARGE ROLLER AND CLEANING BRUSH................................3-24
3.6.5 CLEANING BLADE.........................................................................3-24
3.6.6 DEVELOPER..................................................................................3-25
3.6.7 AFTER REPLACEMENT OR ADJUSTMENT.................................3-26
3.7 TONER SUPPLY MOTOR.......................................................................3-27
3.8 PAPER FEED SECTION .........................................................................3-27
3.8.1 PAPER FEED ROLLER..................................................................3-27
3.8.2 FRICTION PAD ..............................................................................3-27
3.8.3 PAPER END SENSOR...................................................................3-28
3.8.4 EXIT SENSOR ...............................................................................3-28
Non-duplex Models .............................................................................3-28
Duplex Models ....................................................................................3-28
SM iii B121 Series/B259 Series