Ricoh FT5034 Service manual

SERVICE MANUAL

FT5034C

CONTENTS

1. INSTALLATION.................................................... 2

2. OVERVIEW........................................................... 7

3. COPY PROCESS ................................................. 11

4. SECTION DESCRIPTIONS .................................. 13

5. SP MODE/DIP SW TABLE................................... 92

6. CALL SERVICE CONDITIONS ............................ 98

7. PREVENTIVE MAINTENANCE............................105

8. TROUBLESHOOTING..........................................114

9. ELECTRICAL DATA

- 1 -

1. INSTALLATION

1.1 INSTALLATION REQUIREMENTS....................3

1.2 INSTALLATION PROCEDURE..........................4

- 2 -

1.1 INSTALLATION REQUIRE MENTS

more than 10 cm

The installation loca tion should be carefully chose n be cau se en vironmental conditions greatly aff ect the perf ormance of a copier.

1. Environments to Avoid

• Avoid any area exposed to direct sunlight or strong light (Illumination must be

less than 1500 Lux).

• Avoid any area expose d to extre mes of temperature and humidity (standard

condition: 10°C ~ 30°C, 15% ~ 90%).

• Avoid any area expose d to hea te d air fro m a hea te r.

• Avoid any area where tempe rature suddenly changes from low to high or vice

versa.

• Avoid placing the copier in an area filled with dust, and subjected to frequent

strong vibration.

• Avoid narrow space (10 m

2. Access to Copier

Place the copier near a power source, providing clearan ce as shown. The copier must be level within 5 mm both front to rear a nd left to right.

3. Power Connection

• Input voltage level:

220 V/50 Hz, more than 10 A

• Avoid connecting the power cord

to a socket that already has power cords attached

• Permissible voltage fluctuat ion:

220 V (±10%)

• Avoid using a power cord

more than 50 cm

more than 70 cm

more than 80 cm

Front

extension. If you must use one, make sure that it can carry 250 V, 10 A and that it is less than 5 m long.

4. Earth Connection

• Be sure to ground the mach ine prop erly.

• Do not connect the grounding wire to a gas pipe.

- 3 -

1.2 INSTALLATION PROCEDURE

NOTE: 1. When lifting and movin g th e

copier, grasp the black painted stays on each side as shown.

2. When the optional sorter is installed, the above mentioned stays can not be held. Wear gloves to protect hands from the edges of the copier base plate.

3. When transporting the cop ier, remove all the developer and toner inside the machine. Also make sure to lock the scanner with the lock plate.

1. Unpacking and Clamps Removal

1. Remove the shipping tapes from the copier as follows:

1) From platen cover to front cover

2) Manual table

3) Feed guide (cassette insert sectio n)

Scanner Lock Plate Cover

4) Transport guide plate

5) T/S corona unit

6) Toner shield glass

7) Front loading cassett e leve r

8) Operation panel cover

9) PTL, QL filter

10) Relay lower guide plate

2. Remove the seal from the toner tank entrance.

3. Remove the wedge (red) from between the registration rollers.

4. Remove the scanner lock plate cover.

5. Remove the scanner lock plate (1 screw). (Save the scanner lock plate for future use.)

6. Reinstall the scanner lo ck plate cover.

Scanner Lock Plate

Development Lock Leve r

7. Adjust the machine level by tu rning the rubber foot on the base plate.

- 4 -

2. Developer Supply

Charge Corona Unit

Place a clean sheet of pape r on yo ur work surface.

1. Raise the development lock le ver and pu ll out the development unit. Place the unit on a clean shee t of paper.

2. Separate the toner tank from the development unit (2 screws).

3. Pour one bag of developer (1 kg) into the development unit while turn ing the knob counterclockwise to distribute the developer evenly.

4. Remount the toner tank on the development unit.

NOTE: Make sure that there is no gap

between the toner tank and the development unit.

3. Drum Protective Sheet Removal

1. Lower the T/S corona unit lever.

Toner Tank

Drum Protective Sheet

Drum Stay

2. Remove the charge corona unit together with the wire cleaner (1 screw).

3. Remove the drum stay (1 knob and 1 screw). The drum knob is reverse threaded.

4. Pull out the drum prot ect ive sheet.

5. Reinstall the drum stay an d the charge corona unit with the wire cleaner.

6. Raise the T/S corona unit lever.

4. Development Unit Installation

1. When installing the development unit, be sure the development unit rail is pro perly engaged with the unit guide rail on the copier. (Make sure that the PTL and QL filters are in their original position s.)

2. Shake the toner cartridge well and insert the cartridge. (Refer to the ton er sup ply guide decal on the front right cove r.)

Drum Knob

T/S Corona Unit Lever

Toner Cartridge

- 5 -

5. Perform the Drum Conditioning

(This operation must be performed after developer and drum insta llation.)

1. Open the front right cover and move the drum conditioning switch on the re verse side of the operation pan el to the left. Close the front right cover a nd switch the power on. (The Start key changes from red to green after 2 min.)

2. Lower the platen cover and enter "99" using the number keys and press the Sta rt key. (Drum conditioning takes about 5 min.)

3. After the drum conditioning is finished, open the front right cover, move the drum conditioning switch to the right an d close the front right cover.

4. Place the paper size actuato r a nd size decal on the cassette (A4 lengthwise or B5 lengthwise) and load paper into the cassette.

Drum Conditioning Switch

5. Check the machine operation and copy quality.

- 6 -

2. OVERVIEW

2.1 SPECIFICATIONS..............................................8

2.2 GUIDE TO COMPONENTS................................9

- 7 -

2.1 SPECIFICATIONS

Items Specifications Remarks Configuration Desk top Copy Process Dry electrostatic transfer system Originals Sheet/book Original Size Maximum A3 Copy Paper Size Maximum A3, Minimum A6 Lengthwise Copy Paper Weight 52 g/m

Copy Speed

~ 157 g/m

Originals A3 B4 A4 B5 A4R B5R Speed 20 23 34 37 26 30

Warm-up Time Less than 2 min. First Copy Time 4.5 seconds/A4 sideways Copy Number Input 1 to 99, Numeric key pad Paper Feed Three Cassettes (including the front loading

cassette) + Bypass Feed Table Charge System Dual wire corotron system Exposure System Slit exposure

(exposure lamp: 180 V, 320 W) Reproduction

Ratios

Full Size 1 : 1 Reduction 93%, 87%, 82%, 71%, 61%,

Enlargement 115%, 122%, 141% Zoom 50%~200% in 1% steps

Photoconductor Selenium-drum (F type) Development

Magnetic brush system System

Image Density Control

Toner

Development Bias system + Exposure Control

System

Cartridge exchange (300 g): oilless Replenishment

Cleaning Type Cleaning blade and brush with PCC Image Fusing Heat roll type (220 V, 800 W) Image Transfer Corotron system Paper Separation Dual wire ac corona and pick-off pawls Quenching System Photo-quenching Auto Clear All input modes are reset 60 seconds after the

copier is last used. Power Source 220 V/50 Hz, 8 A Power

Consumption

Maximum: Less than 1.5 kW

Average: Warm-up 0.8 kW

Weight 79 kg Dimensions 765 (W) x 666 (D) x 426 (H) mm Peripheral

Sorter and Auto Document Feeder Equipment

50%

Stand by 0.18 kW Copy cycle 1.0 kW

F/L cassette: 64 ~ 90 g/m 1st & 2nd cassette: 52 ~ 127 g/m

By-pass feed: 52 ~ 157 g/m

Cassette: 250 sheets x 3 Bypass Feed: 50 sheets

Reproduction Ratio Change: Full size ↔ Reduction or Enlargement: Less than 3.5 seconds Enlargement ↔ Reduction: Less than 5.0 seconds

- 8 -

2.2 GUIDE TO COMPONENTS

1. Operation Panel

- 9 -

2. Indicator Panel

- 10 -

3. COPY PROCESS

3.1 COPY PROCESS DIAGRAM .............................12

- 11 -

3.1 COPY PROCESS DIAGRAM

Toner

Quenching Lamp

Charge Corona Unit

Erase Lamp

Exposure

Carrier

Cleaning Blade

Cleaning Brush

Pre-Cleaning Corona (PCC)

Pick-off Pawls

1. DRUM CHARGE

In the dark the charge corona unit gives a uniform positive charge to the selenium drum. The charge remains on the surface of the drum because th e photoconductive selenium has high electrical resistance in the dark.

2. ERASE

The erase lamp illumi na tes the areas of the ch arg ed drum surface that wil l no t be use d fo r the cop y imag e. The resistance of the drum in the illumi na ted areas drops and the charge on those areas dissipates.

3. EXPOSURE

An image of the original is ref le ct ed ont o the selenium drum surface via the optics assembly. The charge on the drum surface is dissipated in direct proportion to the intensity of the reflected light, thus producing an electrica l la tent image on th e drum surface.

4. DEVELOPMENT

Negatively charged toner is attracted to the positively charged areas of the drum, thus develop ing th e late nt image. (The negativ e tri bo el ec tric charge is caused by rubbing action between the carrier an d toner particles. )

5. ID SENSOR

The main CPU checks toner density by directly sensi ng the image densit y at the beginning of the fi rst cop y cy cl e after the main switch is turned on, and at every 10th copy after that.

6. PRE-TRANSFER LAMP (PTL)

The PTL illuminates the dr um to remov e al l po si tive charge from the exposed areas of the drum. This prevents the toner particle s from being reatt rac ted to the drum surface during paper separation and makes paper separation easi er.

F TYPE Photoconductor Drum

Separation Corona Wire

Development Roller

ID Sensor

Pre-Transfer Lamp

Paper

Transfer Corona Wire

7. IMAGE TRANSFER

Paper is fed to the drum su rfa ce at th e proper time so as to align the copy pap er an d the developed image on the drum surface . Then, a strong positive charge is applied to the reverse side of the copy paper, providing the electrical force to pull the toner pa rti cl es from the drum surface to the copy pap er. At the same ti me , th e copy paper is electrically attracted to the drum surface.

8. PAPER SEPARATION

A strong ac corona discharge is applied to the reverse side of the copy paper, gradually reducing the positive charge on the copy paper and breaking the electrical attraction between the paper and the drum. Then, the stiffness of the copy paper causes it to separate from the drum surface. The pick-off pawls help paper which has low stiffness to separate from the drum.

9. PRE-CLEANING CORONA (PCC) The PCC applies a positive charge to any toner remaining on the drum after image transfer. This causes repulsion between the toner particles and the drum and thereby makes cleaning more effective.

10. CLEANING

The cleaning brus h removes part of the tone r o n th e drum and loosens the remainder. The cleaning bl ad e then scrape s of f the loosened t on er.

11. QUENCHING

The light fro m th e quenching la mp, which is a cold cathode tube, electrically neutralizes the surface of the selenium drum.

- 12 -

4. SECTION DESCRIPTIONS

4.1 MECHANICAL COMPONENT LAYOUT............14

4.2 DRIVE LAYOUT

(INCLUDING PERIPHERALS) ...........................15

4.3 ELECTRICAL COMPONENT LAYOUT .............16

4.4 PAPER FEED AND REGISTRATION ................18

4.5 OPTICS...............................................................28

4.6 AROUND THE DRUM ........................................44

4.7 DEVELOPMENT AND TONER SUPPLY...........50

4.8 ID SENSOR AND PTL........................................62

4.9 IMAGE TRANSFER, PAPER SEPARATION

AND PAPER TRANSPORT................................71

4.10 CLEANING .......................................................75

4.11 FUSING.............................................................83

4.12 MISFEED CHECK ............................................89

4.13 PULSE GENERATOR ......................................90

4.14 OTHERS...........................................................91

- 13 -

4.1 MECHANICAL COMPONENT LAYOUT

1. 3rd Mirror

2. 2nd Mirror

3. 1st Mirror

4. Exposure Lamp

5. Exposure Glass

6. Hot Roller Stripper

7. Hot Roller

8. Main Motor

9. Transport Belt

10. Lens

11. Cleaning Unit

12. Quenching Lamp

13. Separation Corona Wire

14. Drum

15. Charge Corona Wire

16. Transfer Corona Wire

17. Erase Lamp

18. Development Unit

19. 4th Mirror

20. Feed Roller (By-pass Feed)

21. Toner Tank

22. Pick-up Roller

23. Pressure Lever

24. Pressure Roller

25. Front Loading Ass’y

26. Registration Roller

27. Feed Roller (F/L)

28. Relay Roller

29. Feed Roller (2nd)

30. Friction Pad

31. Feed Roller (1st)

32. 2nd Casse tte

33. 1st Cassette

34. By-pass Feed Table

- 14 -

4.2 DRIVE LAYOUT (INCLUDING PERIPHERALS)

31 30

1234567

2425

2223

10 11

1. DF Feed-out Roller

2. Feed-out Roller Drive Belt

3. Pulse Generator Sprocket/Toner Supply Drive Gear → 34. Development Drive Gear

4. Drum Drive Pulley

5. Drum Drive Belt

6. Cleaning Drive Sprocket

7. 2nd Scanner Drive Pulley

8. Main Motor Sprocket

9. DF Transport Belt

10. DF Belt Drive Motor Gear

11. DF Feed Roller

12. Bin Transfer Wheel

13. Bin Support Rack

14. Bin Support Pinion Gear

15. Bin Drive Motor Gear

16. (Sorter Adapter) Feed Motor Pulley

17. Sorter Adapter Drive Belt

18. Fusing Exit Roller Gear

19. Fusing Drive Release Gear

20. Transport/Fusing Drive Sprocket

21. Cam Wheel

22. Cam Drive Gear

23. Cam Drive Sprocket

24. Main Drive Chain

25. Registration Clutch

26. F/L Feed Clutch

27. 2nd Cassette Feed Clutch

28. Relay Clutch

29. 1st Cassette Feed Clut ch

30. By-pass Feed Clutch

31. Toner Supply Clutch → 35. Toner Supply Drive Gear

32. Scanner Motor Pulley

33. Scanner Drive Wire

- 15 -

4.3 ELECTRICAL COMPONENT LAYOUT

1. Scanner Motor

2. By-pass Feed Clutch

3. Pulse Generator Sensor

4. 1st Cassette Paper End Sen sor

5. By-pass Pick-up Solenoid

6. Feed Control Board

7. Operation Panel Board

8. 1st Feed Clutch

9. Total Counter

10. 2nd Cassette Pap er End Sensor

11. Door Switch

12. Door Switch

13. 2nd Feed C lutch

14. Relay Roller Clutch

15. F/L (Front Loading) Feed Clutch

16. F/L Tray Paper End Sensor

17. Cleaning Solenoid

18. Main Power Relay

19. Main Switch

20. Power Supply Board

21. Lamp Regulator Board

22. Power Transformer

23. Main Fuse

24. Fusing Control Board

25. Noise Filter

26. Power Pack - T/S/PCC

27. Scanner Home Position Sensor

28. Lens Motor

29. Main Motor Capacitor

30. Lamp Stabilizer

31. ADF Control Board

32. 2nd Scanner Home Position Sensor

33. Pick-off Solenoid

34. 2nd Scanner Motor

35. Main Board

36. Registration Clutch

37. Power Pack - C/B

38. Toner Supply Clutch

- 16 -

3939

545352

454647

39. Exposure Lamp

40. Thermofuse

41. Fusing Exit Sensor

42. Fusing Thermistor

43. Main Motor

44. Vacuum Fan

45. Erase Lamp

46. ID Sensor Board

47. PTL (Pre-Transfer Lamp)

48. Registration Sensor Boa rd

49. 2nd Cassette Paper S ize Se nso r

50. 1st Cassette Paper Size Sensor

51. By-pass Table Sensor

52. By-pass Paper End Sensor

53. Optics Cooling Fan

54. Drum Heater

55. QL (Quenching Lamp)

56. Lens Home Position Sensor

57. ADS Sensor

58. Fusing Heater

59. Exhaust Blower

- 17 -

4.4 PAPER FEED AND REGISTRATION

Friction Pad

4.4.1 Mechanical Parts

1. Overview

In total this machine has fo ur feed stations. They are th ree cassette feed stations and a by-pass feed station. The 1st and 2nd feed statio ns ea ch use a size adjustable cassette , bu t the 3rd feed station located inside the copier uses only an A3 cassette. The capacity of each cassette is 250 sheets. The maximum pap er cap acity of the by-pass feed station is 50 she ets. All four feed stations use the feed rolle r and frictio n pa d syste m . On ly the by-pa ss feed station uses a pick-up roller.

2. Feed System

1) Feed Roller The CPU starts paper feed by energizing the appropriate paper feed clutch (the paper feed clutches are all magnetic clutches). The CPU turns on the paper feed clutch for the required station, at a programmed time after the Start key is pressed. Upon receiving the sign al fro m t he registration sensor, th e CPU tu rns of f the paper feed clutch.

Feed Roller

1st Feed Clutch

2nd Feed Clutch

2) Friction Pad Feed System When a cassette is inserte d int o th e copier, the friction pad contacts the feed roller (in the by-pass feed stat ion, it always contacts the feed roller). The friction pad holder is mounted on one end of the swivel plate with a swivel screw, so it automatically applies even pressure against the fee d roller and the copy paper. The coefficients of frictio n are µ 1 > µ 2 > µ3.

Feed Roller

µ1 µ2

The coefficient of friction between the friction pad and paper.

µ1

µ3

µ2

- 18 -

3. Paper End Detection and Paper Size Detection

1) Paper End Detection This machine uses a photointerrupter sensor for paper end detection. The paper end actuator, which is on th e same shaft as the paper end feeler, pivots into the sensor.

2) Paper Size Detection Paper size is detected by an array of five photointerrupt ers in the cassette entrance. The paper size sensors are actuate d by a plate on the front of the cassette. Each paper size has its own unique combina tio n of notches in the act uator plate. (For the front loading feed station , if paper is detected, the copier aut oma tically detects A3 size. The A3 casset te has a paper size actuator in case it is used in the 1st or 2nd feeding stat ion for some reason.)

Size Detection Code

A3 B4 A4 A4R B5 B5R A5 A5R B6 B6R 1 ●●❍●❍●❍●❍● 2❍●❍❍●●❍❍●● 3❍❍●●●●❍❍❍❍ 4❍❍❍❍❍❍●●●● 5❍❍❍❍❍❍❍❍❍❍

Paper Size Sensor

Actuator Plate

Detected: ❍ Not detected: ● Other sizes are indicated as ❋ on the operation panel.

- 19 -

4. Paper Lift Mechanism

Cassette Arm

When a cassette is inserte d int o the copier, the curved release guide s on th e sides of the cassette press against the rollers on the release levers and force the release levers down. The release leve rs rotate the cassette arm shaft, moving the cassette arm down and out of the way.

When the cassette is fully se at ed , the release guides allow the release leve rs to move back up. The cassette arm then presses up the cassette bottom plate until the paper contact s the paper feed roller.

Release Guide

Release Lever

5. Registration

The registration rollers have two fu nct ions. One is to adjust the image leading edge on the drum. Anothe r is to preve nt paper skew.

The registration roller is driven by the registra tio n clut ch and the switch -on timing of the clutch can be adjuste d with DGS103 on the main board in 1 mm step s.

Registration Clutch

Registr ation Rollers

- 20 -

1) Registration Standard

Copy (A4)

(Main Board)

Drum

The registration standard is 0 ± 2mm. If it is 0 mm, the paper lead edge and original lead edge is the same . Bu t du e to lead edge erase, the copy image has a blank margin (3.5 ± 2.5 mm).

Original (A4)

2) Registration Adjustment Registration can be adju ste d by DGS103 on the main board.

Origina l le ad edge posi tion

a: lead edge erase (3.5 ± 0.5 mm) b: registration (0 ± 2 mm) c: lead edge blank margin (a + b =3.5 ± 2.5 mm) d, e: side margin (2 ± 2 mm at each side,

for full size copies. The total of both side margins is less than 4 mm)

TP103

(PSEN)

DGS103

VR101

CN102 CN101

IC107

IC120 IC115

Paper

6. By-pass Feed Station

The by-pass feed table do es no t use the same feed mechanism as the other f ee din g stations. It uses a pick-up rolle r in additio n to the feed roller and friction pad system.

To use a larger size than B4 at the by-pa ss fee d ta ble, the large cassette must be installed in order to support the tra iling part of the paper.

When the by-pass feed table is opened, the pick-up soleno id tu rns on and off once , The by-pass feed table, add pap er, and inte rrupt indicators turn on, and the Start key turns red.

- 21 -

When paper is loaded onto th e by-p ass feed table, the paper end sen sor is

Feed Roller (2nd)

de-actuated and Sta rt key tu rns green. When the Start key is pressed, the pick-up roller is lo were d by th e by-pass pick-up

solenoid to conta ct th e pa pe r stack. When the paper reaches the fee d rolle r, th e pick-up roller moves up away from the pape r stack.

The size of copy paper is measured at the by-pa ss fee d sta tio n from the first copy as follows. While the copy paper passe s under the registration sensor, the sensor output changes from low to hig h. The CPU cou nt s the perio d of the high signa l and calculates the paper len gth. The scanner return po sitio n corre sponds to this calculated paper leng th.

When the by-pass feed table is opened, the by-pass table se nso r (a photo interrupter) is activated and the copier enters by-p ass feed mode.

The by-pass feed mode is the same as interrupt mode. When the by-pa ss f ee d ta ble is opened, the copier stores th e pre vious job settings in memory.

When the by-pass table is opened, the operator can use the 1st and 2nd cassette stations before load ing pap er on to the by-pass feed table. Howe ver, whenever paper is loaded onto the by-pass f ee d ta ble , other feeding statio ns can no t be select ed .

7. Front Loading Feed

The front loading fee d sta tion is located at the bottom of the copier. This is only an A3 paper feeding station. The F/L tray pape r end senso r (a pho tointerrupter) on the rear side plate detects bo th paper end and whether or not th e front loading station is in position.

The direction of the pap er pa th is:

Feed Roller → Relay Roller → Registration Roller → T/S Corona Unit

Registration Roller

Feed Roller

Front Loading Cassette

Relay Rol ler

- 22 -

8. Electrical Control

Signal I/O

Main Control Board

CN NO. Signal Level Size 1 I 102–24B Detection: 5 V Size 2 I 102–22A Size 3 I 102–24A

No detection: 0 V

Size 4 I 102–22B Size 5 I 102–25A Paper End 1 I 102–23B Paper end: Paper End 2

I 102–25B

detection

1st Feed MC O 101–5A 2nd Feed MC O 101–3A By-pass Feed MC O 101–10A

24 V

F/L Feed MC O 101–2A Relay Roller MC O 101–15A Registration MC O 101–14B By-pass Feed Table Sensor Registration Sensor

I 101–15A

closed

5 V

no paper

I 101–4A

open

paper

Scan Signal

T0 → 1st feed station

size detection

→ 1st feed station

paper end detection

→ By-pass feed

paper end detection

T1 → 2nd feed station

size detection

→ 2nd feed station

paper end detection

→ By-pass feed

station table open detection

4.4.2 Replacement and Adjustment

1. Paper Size Sensor Replacement (1st and 2nd feed stations)

1. Remove the paper size sensor from the

sensor bracket (1 screw).

2. Remove the connector an d rep lace the

sensor.

Paper Size Sensor

- 23 -

2. By-pass Feed Table Replacement

Upper By-pass Feed Guide Plate

1. Open the by-pass fe ed tab le an d remove

the by-pass feed table hinges from the positioning pins by pressing them inward .

2. Remove the by-pass feed table.

3. Feed Rollers and Friction Pads Replacement

NOTE: Replace the feed roller and th e

friction pad as a set to maintain a good paper feed and separation ability.

Snap Ring

1. By-pass Feed Station

1) Remove the by-pass feed tab le.

By-pass Feed Table

Friction Pad

MT78

2) Remove the upper by-pass fee d gu ide plate (2 screws).

3) Remove the pick-up roller, feed roller, and gear (2 snap rings).

NOTE: When reinstalling the feed

roller, make sure that the hub is positioned toward the rear on

Hub

Pick-up Roller

Feed Roller

Friction Pad Holder

the shaft.

4) Remove the friction pad hold er by pressing the lower hooks using long no se pliers.

5) Peel off the friction pad and stick a new pad on the friction pad holder.

NOTE: Check that the friction pad is

A = 0.05 ~ 0.35 mm

(Front)

0.05 to 0.35 mm below the surface of the front lip .

6) Grease both sides of the friction pad hold er with Mobil Temp 78.

7) Reinstall the friction pad holde r and the by-pa ss fee d ta ble . NOTE: 1) Do not touch the surface of the new friction pad with oily fingers.

2) Be careful not to damage the pressu re sprin gs.

3) The lip side should be positio ned towards the outside of the machine.

- 24 -

2. 1st and 2nd Feed Stations

Pad Positioning Mechanis m

Friction Pad Holder

Hub

1) Remove the feed roller and hub (1 snap ring).

NOTE: When reinstalling the feed

roller, make sure that the hub is positioned toward th e rea r on the shaft.

2) Remove the cassette arm (2 screws).

3) Mark the position of the eccentric cam groove on the friction pad holder.

Friction Pad

Eccentric Cam

4) Remove the friction pad holder (1 screw and 1 eccentric cam).

5) Peel off the friction pad and stick a new pad on the friction pad holder.

NOTE: Check that the friction pad is 0.05

to 0.35 mm below the surface of the front lip.

6) Clean and grease the swivel surface of the friction pad holder with Mobil Temp 78.

7) Reinstall the friction pad holder. NOTE: Be sure the legs of the friction pad holder are positioned und er th e

spring loaded pad positio nin g mechanism. The eccentric cam should be secured in the origin al po sitio n referring to the mark made in step 3).

MT78

Feed Roller

A = 0.05 ~ 0.35 mm

Cassette Arm

(Front)

4. F/L Feed Station

1. Pull out the F/L tray and remo ve th e A3 cassette.

2. Remove the screw securing the feed roller bracket.

3. Remove the F/L feed roller (1 snap ring). NOTE: When reinstalling the feed roller,

make sure that the hub is positioned towa rd th e front on the shaft.

4. Remove the friction pad assembly (1 stepped screw).

- 25 -

Feed Roller

Hub

Feed Roller Bracket

Friction Pad Assembly

5. Mark the position of the eccentric cam

MT78

groove on the friction pad holder.

Eccentric Cam

Friction Pad Holder

6. Remove the friction pad holder f rom th e holder bracket (1 screw and 1 eccentric cam).

7. Peel off the entrance mylar and the friction pad and stick new ones on the friction pad holder.

NOTE: Check that the friction pad is 0.05

to 0.35 mm below the surface of the front lip. Make sure that the overlapping length of the entrance mylar on the friction pad (P) is 2.5 to 3 mm.

Holder Bracket

Entrance Mylar

2.5 ~ 3.0 mm

8. Clean and grease the swivel surface of the friction pad holder with Mobil Temp

78.

9. Reinstall the friction pad hold er on the hold er bra cket . NOTE: The eccentric cam should be secure d in the original position refe rring to

the mark made in step 5).

10. Clean and grease the swivel surface of the holde r b racke t with Mo bil Temp 78.

11. Reattach the friction pad assemb ly to the F/L fee din g sta tio n. NOTE: Be sure the legs of the friction pa d ho lde r are po sitio ne d unde r the

spring loaded pad positioning mechanism. Make sure that the pressure spring is properly positioned and the frictio n pa d asse mbly swivels smoothly.

- 26 -

5. Friction Pad Pressure Adjustment

(fig. 2)

NOTE: This adjustment is require d when multifeeds or misfeeds occur with th e

customer’s brand of paper. If replacement of the fee d rolle r and the frictio n pa d does no t solve the problem, do the following adjustment.

1. Remove the cassette.

2. Turn the eccentric cam [A] to adjust the friction pad pressure as shown in figu res 1 and 2.

NOTE: If the eccentric ca m groove is

aligned vertically, the gap between the feed roller and the friction pad will become narrower or wider as shown in figure 3.

• When multifeed occurs, make

the gap narrower.

• When misfeed occurs, make the

gap wider.

[A]

(fig. 1)

Narrow Normal Wide

(fig. 3)

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4.5 OPTICS

2nd Mirror

Scanner Motor

4.5.1 Mechanical Parts

1. Overview

Exposure La mp

3rd Mirror

Reflector

1st Mirror

Lens

4th Mirror

Toner Shield Glass

During the copy cycle, an image of the original is reflecte d onto the drum surface via the optics assembly as follows.

Light path: Exposure Lamp → Original → First Mirror → Second Mirror → Third Mirror → Lens → Fourth Mirror → Ton er Sh ield Glass → Drum (When the exposure lamp is positioned close to the far left, it is at the home position.)

This model has ten standard repro du ctio n ratios: six reductions, three enla rge ments, and full size. In addition, it has a zoom fu nct ion.

The user can change th e rep roduction ratio in one perce nt st eps f rom 50 % to 200 %. This machine has an automatic ima ge control system in which the copier comput es

the correct image density and adjusts the deve lop ment bias as a result of measuring the original background densit y using the ADS sen sor.

2. Scanner Drive

1st Scanner

2nd Scanner

Scanner Drive Wire

Damper wheel

Scanner Home Position Sensor

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This model uses a dc servomotor to drive th e scanners.

Lens Drive Wire

Full Size

(Reduction)

The scanner motor chan ge s the scann er spe ed dep en din g on the reproduction ratio.

3. Lens/Mirror Positioning

The lens motor (a stepping motor) changes the lens and 2nd scanner posit ion in accord an ce with the selected rep roduction ratio to provide

Lens Drive Pulley

Lens Home Position Sensor

the proper optical dista nce between the lens and the drum surface.

1. Lens Positioning The output gea r o f th e lens motor engages the gear of the lens drive pulley directly.

Lens Drive Bracket

The lens drive wire is wrapped around the lens drive pulley and is connected to the

Lens Motor

lens drive bracket. As the lens mot or is a stepper motor, the rotation of the lens drive pulley moves the lens back and forth in discrete steps. The lens home position sensor informs the optics CPU (IC403) when the lens is at the

Lens Movement

Lens H.P. Sensor

(Enlargement)

full size position (home position). The optics CPU determines the lens stop position in reduction and enlargement modes by counting the number of steps the motor makes. When the reproduction rat io is chan ged, the lens moves directly to th e sele cted lens position. When the lens moves from one enlargement ratio to another or from one reduction ratio to ano th er, it does not moves to the home position.

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