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11. Charge corona section

Theory of operation ver. 1.0  July. 2006

26

magicolor 2490MF

Composition/Operation

11. Charge corona section

11.1 Composition

4139T2C513AA

4139T2C512AA

4139T2C505AA

Charge Corona

Electrode

Grid mesh

Summary of Contents for Magicolor 2490 MF

Page 1: ...SERVICE MANUAL 2006 07 2006 07 Ver 1 0 Ver 1 0 magicolor 2490MF THEORY OF OPERATION ...

Page 2: ...NING INDICATIONS ON THE MACHINE S 18 MEASURES TO TAKE IN CASE OF AN ACCIDENT S 20 Composition of the service manual C 1 Notation of the service manual C 2 magicolor 2490MF Main Unit Outline 1 Composition Operation 9 Auto Document Feeder Unit Outline 1 Composition Operation 3 Lower Feeder Unit Outline 1 Composition Operation 3 Duplex Option Outline 1 Composition Operation 3 ...

Page 3: ...ii ...

Page 4: ...rse of technical training and even after that for performing maintenance and control of the product properly Keep this Service Manual also for future service In this Service Manual each of three expressions DANGER WARNING and CAUTION is defined as follows together with a symbol mark to be used in a limited meaning When servicing the product the relevant works disassembling reassembling adjustment ...

Page 5: ...erformance and safety Such modifications are therefore strictly prohibited the points listed below are not exhaustive but they illustrate the reason ing behind this policy SAFETY WARNINGS Prohibited Actions DANGER Using any cables or power cord not specified by KMBT Using any fuse or thermostat not specified by KMBT Safety will not be assured leading to a risk of fire and injury Disabling fuse fun...

Page 6: ...cable having enough cur rent capacity and the cord set meets regulatory requirements for the area Use of inadequate cord set leads to fire or electric shock Attach power plug which meets the following criteria having configuration intended for the connection to wall outlet appropriate for the product s rated voltage and current and the plug has pin terminal s for grounding and meets regulatory req...

Page 7: ...er leads to the product connecting to inadequate power supply voltage current capacity grounding and may result in fire or electric shock If proper wall outlet is not available advice the customer to contact qualified electrician for the installation Plug the power cord into the dedicated wall outlet with a capacity greater than the maximum power consumption If excessive current flows in the wall ...

Page 8: ...o a risk of fire Check whether the power cord is damaged Check whether the sheath is damaged If the power plug cord or sheath is damaged replace with a new power cord with plug and connector on each end specified by KMBT Using the damaged power cord may result in fire or electric shock Do not bundle or tie the power cord Overheating may occur there leading to a risk of fire Check whether dust is c...

Page 9: ...not use an extension cable reel with the cable taken up Fire may result Prohibited Installation Places WARNING Do not place the product near flammable materials or vola tile materials that may catch fire A risk of fire exists Do not place the product in a place exposed to water such as rain A risk of fire and electric shock exists When not Using the Product for a long time WARNING When the product...

Page 10: ...ion before Servicing CAUTION Before conducting an inspection read all relevant docu mentation service manual technical notices etc and proceed with the inspection following the prescribed pro cedure using only the prescribed tools Do not make any adjustment not described in the documentation If the prescribed procedure or tool is not used the prod uct may break and a risk of injury or fire exists ...

Page 11: ... risk of elec tric shock exists Safety Checkpoints WARNING Check the exterior and frame for edges burrs and other damage The user or CE may be injured Do not allow any metal parts such as clips staples and screws to fall into the product They can short internal circuits and cause electric shock or fire Check wiring for squeezing and any other damage Current can leak leading to a risk of electric s...

Page 12: ...ng a lithium battery replace it with a new lith ium battery specified in the Parts Guide Manual Dispose of the used lithium battery using the method specified by local authority Improper replacement can cause explosion After replacing a part to which AC voltage is applied e g optical lamp and fixing lamp be sure to check the installa tion state A risk of fire exists Check the interlock switch and ...

Page 13: ... breathe excessive amounts or let the substances come into contact with eyes etc It may be stimulative If the substances get in the eye rinse with plenty of water immediately When symptoms are noticeable consult a physician Never throw the used cartridge and toner into fire You may be burned due to dust explosion Handling of Service Materials CAUTION Unplug the power cord from the wall outlet Drum...

Page 14: ...eaner at a time and take care not to spill any liquid If this happens immediately wipe it off A risk of fire exists When using any solvent ventilate the room well Breathing large quantities of organic solvents can lead to discomfort Handling of Service Materials CAUTION ...

Page 15: ...e of the Print Head Unit This product employs a Class 3b laser diode that emits an invisible laser beam The laser diode and the scanning polygon mirror are incorporated in the print head unit The print head unit is NOT A FIELD SERVICE ITEM Therefore the print head unit should not be opened under any circumstances Semiconductor laser Maximum power of the laser diode 10 mW Maximum average radiation ...

Page 16: ...and must be attached to laser products marketed in the United States CAUTION Use of controls adjustments or performance of procedures other than those spec ified in this manual may result in hazardous radiation exposure All Areas CAUTION Use of controls adjustments or performance of procedures other than those spec ified in this manual may result in hazardous radiation exposure Denmark ADVARSEL Us...

Page 17: ...en utsättas för osynlig laserstrålning som överskrider gränsen för laser klass 1 VARNING Osynlig laserstrålning när denna del är öppnad och spärren är urkopplad Betrakta ej strålen Norway ADVERSEL Dersom apparatet brukes på annen måte enn spesifisert i denne bruksanvisning kan brukeren utsettes for unsynlig laserstråling som overskrider grensen for laser klass 1 LOUKAN 1 LASERLAITE KLASS 1 LASER A...

Page 18: ...S 15 4 2 Laser Safety Label A laser safety labels is attached to the outside of the machine as shown below 4139P0E501DA COMPLIESWITH 21 CFR 1040 10 AND 1040 11 EXCEPT FOR DEVIATIONS PURSUANTTO LASER NOTICE NO 50 DATED JULY 26 2001 or and ...

Page 19: ...SAFETY AND IMPORTANT WARNING ITEMS S 16 4 3 Laser Caution Label A laser caution label is attached to the inside of the machine as shown below 4139P0E503DA ...

Page 20: ...disassembly job needs to be performed in the laser beam path such as when working around the printerhead and PC Drum be sure first to turn the copier OFF If the job requires that the copier be left ON take off your watch and ring and wear laser protective goggles A highly reflective tool can be dangerous if it is brought into the laser beam path Use utmost care when handling tools on the user s pr...

Page 21: ... shown are attached in some areas on in the machine When accessing these areas for maintenance repair or adjustment special care should be taken to avoid burns and electric shock WARNING INDICATIONS ON THE MACHINE 4139P0E504DA High temperature High voltage ...

Page 22: ...A High voltage You may be burned or injured if you touch any area that you are advised not to touch by any caution label Do not remove caution labels If any caution label has come off or soiled and therefore the caution cannot be read contact our Service Office ...

Page 23: ...of a serious accident has been received from a customer an on site evalua tion must be carried out quickly and KMBT must be notified 3 To determine the cause of the accident conditions and materials must be recorded through direct on site checks in accordance with instructions issued by KMBT 4 For reports and measures concerning serious accidents follow the regulations speci fied by every distribu...

Page 24: ...formation The basic configuration of each section is as follows However some options may not be applied to the following configuration Theory of Operation section Field service section OUTLINE Explanation of system configuration product specifications unit configuration and paper path COMPOSITION OPERATION Explanation of configuration of each unit operating system and control system GENERAL Explan...

Page 25: ...eeding on the media size No specific notation is added for the long edge feeding When the size has only the short edge feeding with no long edge feeding S will not be added to the media size Sample notation 1 IC board Standard printer 2 magicolor 2490MF Main body 3 Microsoft Windows 95 Windows 95 Microsoft Windows 98 Windows 98 Microsoft Windows Me Windows Me Microsoft Windows NT 4 0 Windows NT 4 ...

Page 26: ...SERVICE MANUAL 2006 07 Ver 1 0 THEORY OF OPERATION Main Unit magicolor 2490MF magicolor 2490MF ...

Page 27: ... represents the number of times the revision has been made To indicate clearly a section revised show in the lower outside section of the correspond ing page A number within represents the number of times the revision has been made NOTE Revision marks shown in a page are restricted only to the latest ones with the old ones deleted When a page revised in Ver 2 0 has been changed in Ver 3 0 The revi...

Page 28: ...ock diagram 12 7 Scanner section IR section 13 7 1 Composition 13 7 2 Drive 14 7 3 Operation 15 7 3 1 IR unit open close mechanism 15 7 3 2 Auto document feeder unit open close 17 7 3 3 Original size detection 17 8 Write section PH section 18 8 1 Composition 18 8 2 Operation 19 8 2 1 Outline 19 8 2 2 Laser exposure process 19 8 2 3 Laser emission timing 20 8 2 4 Laser emission area 20 9 Cartridge ...

Page 29: ...ck 32 13 Image transfer section 38 13 1 Composition 38 13 1 1 1st transfer section 38 13 1 2 2nd transfer section 39 13 2 Drive 40 13 3 Operation 40 13 3 1 Transfer belt cleaning mechanism 40 13 3 2 1st transfer roller voltage ON OFF control 44 13 3 3 2nd transfer roller pressure retraction mechanism 44 13 3 4 2nd transfer roller cleaning 46 13 3 5 Neutralization and separation of paper 47 13 3 6 ...

Page 30: ... 17 1 Composition 59 17 2 Drive 60 17 3 Operation 60 17 3 1 Heating Roller drive control 60 17 3 2 Fusing temperature control 62 17 3 3 Protection against abnormally high temperature 66 17 3 4 PPM control 67 18 Paper exit section 68 18 1 Composition 68 18 2 Drive 69 18 3 Operation 69 18 3 1 Exit tray full detection 69 19 Image stabilization control 70 19 1 Overview 70 19 2 Operation 71 19 2 1 Leak...

Page 31: ...magicolor 2490MF Outline Composition Operation Theory of operation ver 1 0 July 2006 iv 20 1 1 Construction 73 20 1 2 Control 74 20 2 Temperature humidity sensor 75 20 2 1 Composition 75 ...

Page 32: ...0 July 2006 1 System configuration 1 magicolor 2490MF Outline Outline 1 System configuration Machine front view Standard for U S A and europe 1 magicolor 2490MF 3 Lower feeder unit 2 Duplex option 4 Dust cover 4139T2E562AA 1 2 3 ...

Page 33: ...x 300 dpi Print resolution 2400 x 600 dpi 1200 x 600 dpi 600 x 600 dpi Copy resolution 600 x 600 dpi Platen Stationary Original scanning Scanning in main scanning direction with a CCD Registration Rear left edge Paper feeding system Tray1 200 sheets Tray2 500 sheets Option Developing system Single element developing system Charging system DC comb electrode scorotron system Image transfer system In...

Page 34: ...2 to 216 mm 3 1 2 to 8 1 2 inch Paper length 148 to 356 mm 5 3 4 to 14 inch Media types Plain paper 60 to 90 g m2 16 to 24 lb Recycled paper 60 to 90 g m2 16 to 24 lb Transparencies Thick stock 91 to 163 g m2 25 to 40 lb Postcards Envelopes Letterhead Label stock Glossy stock Tray capacities Plain paper and letterhead 200 sheets Transparencies thick stock postcards labels stock and glossy stock 50...

Page 35: ...8 F or less per hour Humidity 15 to 85 with a fluctuation of 20 or less per hour CPU Embedded RISC processor 48MHz Standard memory SDRAM 128 MB on IPB 16 MB on LANB Optional memory Not supported Interfaces Host PC interface USB device High speed mode 480 Mbps Camera direct interface USB Host Full speed mode 12 Mbps Network interface Ethernet 10 100 BaseT PSTN line Fax RX TX Telephone line jack Ext...

Page 36: ...4 up to 33 6 Kbps Transmit speed 3 Second page at V 34 Compression MH MR MMR JBIG Memory for receiving 4 MB for fax RX approx 250 pages included in 32 MB NAND flash Remote setting Available via USB Network Paper size A4S LegalS LetterS Functions One touch dial 9 one touch key on operation panel Speed dial 100 fax numbers Group dial 9 groups 50 destination stations for one group Broadcast Available...

Page 37: ...ross section Option 1 Fusing section 7 Toner cartridge section 2 Duplex unit section 8 Drum cartridge section 3 2nd transfer section 9 Transfer belt section 4 Lower feeder section 10 IR section 5 Paper feed section 11 Auto document feeder section 6 Write section 4139T1C501AA 11 1 2 4 3 6 7 8 9 10 5 ...

Page 38: ...Theory of operation ver 1 0 July 2006 4 Paper path 7 magicolor 2490MF Outline 4 Paper path Machine right side view Machine front view 4139T1C502AA 4139T1C504AA ...

Page 39: ... Image creation process 4139T1C503AA 1 CCD Photoelectric conversion 2 Image processing board 3 Laser exposure 4 Photo conductor 5 Photo conductor charging 6 Developing 7 1st image transfer 8 2nd image transfer 9 Paper separation 11 Transfer belt cleaning 12 Fusing 10 Photo conductor cleaning ...

Page 40: ...the surface of the photo conductor It is thereby changed to a visible developed image A DC negative bias voltage is applied to the developing roller thereby preventing toner from sticking to the background image portion 7 1st image transfer A DC positive voltage is applied to the backside of the transfer belt thereby allowing the visible developed image on the surface of the photo conductor to be ...

Page 41: ...5 Image creation process Theory of operation ver 1 0 July 2006 10 magicolor 2490MF Outline Blank Page ...

Page 42: ...n sequence Fusing Motor M4 Print Request Main Motor M1 Polygon Motor Charge output 1st transfer output 2nd transfer output 2nd Transfer Roller retracted Pressure Retraction Solenoid Cleaning Blade SD3 Developing Motor M3 C TOD Rack Motor M2 Tray1 Paper Pick up Solenoid SD1 Registration Roller Solenoid SD2 Registration Sensor PS1 Exit Sensor PS7 4139T2E566AA ...

Page 43: ...d PRCB Image processing board IPB Write unit PH CPU Image processing Operation panel CCD unit Scanner motor Various IR sensors IR Paper pick up transport Image process Control system line Image bus line Fusing Power supply high voltage IR cooling f an motor Lower feeder uni t Duplex uni t IR unit open close sensor DC power supply2 Auto document feeder NCUB LANB ...

Page 44: ... ver 1 0 July 2006 7 Scanner section IR section 13 magicolor 2490MF Composition Operation 7 Scanner section IR section 7 1 Composition 4139T2C502AA 4139T2C568AA 4139T2C565AA Scanner unit Scanner motor IR cooling fan motor ...

Page 45: ...7 Scanner section IR section Theory of operation ver 1 0 July 2006 14 magicolor 2490MF Composition Operation 7 2 Drive 4139T2C566AA ...

Page 46: ... car tridge drum cartridge and other disposables to be replaced with new ones Pulling the IR unit lock release lever will disengage the IR unit lock pawl allowing the IR unit to be opened The IR unit lock release lever is however locked to prevent the IR unit from being opened when the auto document feeder unit is raised open This is done to prevent the machine from toppling over 4139T2C547AA IR u...

Page 47: ...er will disengage the IR unit lock pawl allowing the IR unit to be opened When the auto document feeder unit is raised open the ADF lever is pushed upward to lock the IR unit lock release lever thus preventing the IR unit from being opened 4139T2C550AA IR unit lock pawl IR unit lock release lever 4139T2C548AA IR unit in locked condition IR unit in unlocked condition ADF lever ...

Page 48: ... rotated through cou pling of gears This causes the auto document feeder unit to be secured to the IR unit 7 3 3 Original size detection Since the scanner is not mounted with any original size detection sensors the scanning range of the scanner is determined according to the paper size setting made on the con trol panel If the correct paper size is not selected on the control panel or the paper of...

Page 49: ...n ver 1 0 July 2006 18 magicolor 2490MF Composition Operation 8 Write section PH section 8 1 Composition 4139to2002c0 4139T2C503AA 4139T2C511AA SOS mirror G2 lens Semiconductor laser SOS sensor G1 lens Polygon mirror Return mirror G2 lens SOS lens ...

Page 50: ... lines are scanned with two laser beams emitted from these two LD elements through a single face of the polygon mirror 8 2 2 Laser exposure process 1 The laser light emitted from the semiconductor laser strikes the polygon mirror 2 The polygon mirror with four faces is rotated at high speeds by the polygon motor 3 The SOS sensor ensures that the laser light emission start timing remains constant f...

Page 51: ...for each main scan line 8 2 4 Laser emission area A Main scan direction The print start position in the CD direction is determined by the CD print start signal HSYNC that is output from the image processing board and the width of the paper The laser emission area is determined by the paper size The area of 4 mm on both edges of the paper is however the void image area B Sub scan direction The prin...

Page 52: ...eory of operation ver 1 0 July 2006 9 Cartridge section 21 magicolor 2490MF Composition Operation 9 Cartridge section 9 1 Composition 4139T2C504AA 4139to2053e0 Drum Cartridge 4139to2054e0 Toner Cartridge ...

Page 53: ...is turned OFF and ON or the front door is closed If no new DC is detected the image stabilization sequence is not carried out If a new DC is detected the image stabilization sequence is carried out B Reaching the life The life counter is reset when a new DC is detected The machine gives a warning screen when the life value is reached After a predeter mined number of printed pages are produced afte...

Page 54: ...r a toner cartridge has been detected the machine determines whether it is new or not based on the data acquired D Toner cartridge near empty and empty condition detection The amount of toner consumed is calculated from the number of dots produced for one printed page by the controller A toner near empty condition and a toner empty condition are thereby detected Toner near empty decision The machi...

Page 55: ...24 magicolor 2490MF Composition Operation 10 Photo conductor section 10 1 Composition 10 2 Drive 4139to2056e0 Drum Cartridge Photo Conductor Charge Generating Layer Aluminum Base Charge Transport Layer 4139to2057e0 4139T2C505AA Main Motor Photo Conductor 4139to1058e0 ...

Page 56: ...y the main motor When the main motor is energized it turns the drive gear which in turn rotates the photo conductor 10 3 2 Photo conductor cleaning mechanism The cleaning blade is pressed up against the surface of the photo conductor scraping residual toner off the surface The toner scraped off the surface of the photo conductor is collected in the drum car tridge 4139to2059e0 Cleaning Blade ...

Page 57: ... corona section Theory of operation ver 1 0 July 2006 26 magicolor 2490MF Composition Operation 11 Charge corona section 11 1 Composition 4139T2C513AA 4139T2C512AA 4139T2C505AA Charge Corona Electrode Grid mesh ...

Page 58: ...1 2 1 Charge corona unit ON OFF control The grid voltage Vg applied to the grid mesh is controlled by image stabilization control 4139to2060e0 Y M C K Y K Toner Developing Position Standby Position Belt Positioning Sensor Activated Developing Motor M3 Charge output bias Polygon Motor Energized Rack Motor M2 Main Motor M1 ...

Page 59: ...2 Developing section 12 1 Composition 4139T2C514AA 4139T2C515AA 4139T2C504AA 4139T2C516AA 4139T2C559AA Main motor M1 Developing motor M3 Hopper Supply roller Developing roller Regulator blade 2nd Regulator blade 1st Agitating blade Photo conductor Cleaning blade Waste toner Agitating screw Charge corona ...

Page 60: ...When the toner cartridge rack is stationery at the developing position the developing roller drive gear comes into mesh with the intermediate gear The developing roller is then rotated through the drive provided by the developing motor and intermediate gear 4139T2C517AA Photo conductor Main motor M1 Developing motor M3 Developing roller 4139T2C518AA Developing roller drive gear Intermediate gear D...

Page 61: ... time regulator blade 1st and 2nd regulate the height of toner on the surface of the developing roller 4 Toner then sticks to the electrostatic latent image formed on the surface of the photo conductor That part of toner left on the surface of the developing roller is returned to the toner supply portion Y M C K Y K Toner Developing Position Standby Position Belt Positioning Sensor Activated Print...

Page 62: ...age is applied only during development At any time other than the development only the DC component of the developing bias voltage is applied The developing bias voltage Vb is supplied by the high voltage unit 12 2 4 Developing system The machine employs the single component non contact developing system In the non contact single component developing system the magnetic brush does not rub the surf...

Page 63: ... toner cartridges The rack employs a rotary system Development of the image of each color of toner is performed by rotating the toner car tridge rack A Toner cartridge rack drive The toner cartridge rack is driven by the rack motor Y Toner Cartridge K Toner Cartridge C Toner Cartridge M Toner Cartridge 4139to2064e0 4139to1528c0 Rack Motor 4139to2065e0 4139T2C556AA Rack Motor ...

Page 64: ...e rack is located at this standby position when the machine completes a warm up cycle or waits for a print com mand The development position refers to the position at which the toner cartridge rack stops during development of a specific color of toner The cartridge replacement position refers to the position at which the toner cartridge rack is stopped for replacement of the toner cartridge of a s...

Page 65: ... 2 When a print request is received from the controller the toner cartridge rack is rotated to bring the K toner cartridge to its developing position 3 Development of monochrome printing is started 4 When the development is completed the toner cartridge rack is rotated and brought to a stop at the standby position K Y 70 Cartridge Replacement Position K Developing Position C M 4139to2069e0 K Y C M...

Page 66: ... to bring the M toner cartridge to its developing position 5 Development of M is carried out 6 Similarly the toner cartridge rack is rotated and development of C is carried out 7 Similarly the toner cartridge rack is rotated and development of K is carried out 8 When the development of K is completed the toner cartridge rack is rotated and brought to a stop at the standby position K Y Y Y M C K K ...

Page 67: ...n of the K toner cartridge The Y toner cartridge is therefore provided with a slit for detecting the K developing position When the toner cartridge rack is rotated the rack positioning sensor moves past the slit for detecting the K developing position This allows the machine to determine that the current development is for K Through pulse control of the rack motor the machine then successfully bri...

Page 68: ... rack is rotated from the standby position 45 through pulse control of the rack motor 3 Cartridge replacement position When a request is made for replacing the toner cartridge of a specific color of toner by means of an input from the control panel upon a toner empty condition or through an input made via the printer driver the toner cartridge rack is rotated 70 from the devel oping position throu...

Page 69: ...on Operation 13 Image transfer section 13 1 Composition 13 1 1 1st transfer section 4139T2C519AA 4139to2019c0 4139T2C506AA Driven roller Transfer belt 1st transfer roller Transfer belt drive roller Belt positioning sensor PS4 Photo conductor Toner collecting screw Cleaning blade IDC sensor IDC ...

Page 70: ... magicolor 2490MF Composition Operation 13 1 2 2nd transfer section 4139T2C506AA 4139T2C520AA 4139to2020c0 4139T2C521AA 2nd transfer roller Pressure Retraction slider Pressure Retraction roller Pressure retraction clutch Pressure Retraction slider 2nd transfer roller ...

Page 71: ...ere is a cleaning blade pro vided The cleaning blade is pressed up against the transfer belt thereby scraping residual toner off the surface of the transfer belt The toner collecting screw conveys toner scraped off by the cleaning blade onto the drum cartridge 4139T2C522AA Main motor M1 Transfer belt unit 1st transfer Roller Transfer belt drive roller 2nd transfer roller Driven Roller Cleaning Bla...

Page 72: ...ut The cleaning blade is normally in pressed contact with the transfer belt 1 Pressure retraction operation The cleaning blade pressure retraction operations are performed by the main motor pressure retraction solenoid cleaning blade pressure cam lever and retraction position sensor cleaning blade When the pressure retraction solenoid cleaning blade is energized drive from the main motor is transm...

Page 73: ...e is retracted it results in the cleaning blade being retracted from the transfer belt 6 During this time the retraction position sensor cleaning blade detects whether or not the cleaning blade is retracted from the transfer belt Pressure Retraction Solenoid Cleaning Blade SD3 Main Motor M1 Retraction Position Sensor Cleaning Blade PS6 SD3 Energization Signal after Main Motor has been energized Pr...

Page 74: ...ing blade is returned Then the cleaning blade is pressed against the transfer belt 5 Home position detection The position of the cleaning blade is unknown when the power switch is turned ON or the cover is opened and closed the machine performs a home position detection sequence during a warm up cycle During the warm up cycle the pressure retraction solenoid cleaning blade is energized to start a ...

Page 75: ...ed from the transfer belt A Pressure retraction operation The pressure retraction operation is performed by the main motor pressure retraction solenoid 2nd image transfer and pressure retraction clutch When the pressure retraction solenoid 2nd image transfer is energized drive from the main motor is transmitted to the pressure retraction clutch 4139T2E575AA TOD Image Write Start signal 1st Transfe...

Page 76: ... sequence 1 When the pressure retraction solenoid 2nd image transfer is energized in the con dition in which the 2nd transfer roller is pressed against the transfer belt the pres sure retraction clutch rotates a half turn This moves the pressure slider 2 When the pressure slider is moved the 2nd transfer assy which has been pushed up by the ribs on the pressure slider lowers 3 When the 2nd transfe...

Page 77: ...er roller The toner transferred back to the transfer belt is collected by the cleaning blade A Operation timing The 2nd transfer roller cleaning sequence is carried out under any of the following timings Power switch is turned ON Cover is opened and closed A media error occurs during a print cycle A paper empty condition occurs during a print cycle A paper size error occurs during a print cycle Tr...

Page 78: ...ned correctly with each other on the surface of the transfer belt The position of the transfer belt is detected when the belt positioning sensor detects detection holes provided in the transfer belt There are two detection holes provided in the transfer belt The image write start position is varied according to the paper size For a paper size of A4 or smaller the image write start position is alig...

Page 79: ...uctor ground The resistance of the transfer belt is thereby measured 2 Based on the measured resistance value the optimum 1st transfer voltage is established C 2nd transfer ATVC operation 1 The data on the 2nd transfer constant current output from the high voltage unit is fed back to the high voltage unit via the 2nd transfer roller transfer belt and the transfer belt drive roller The resistance o...

Page 80: ...ion Operation 14 Toner collecting section 14 1 Composition 14 2 Drive 4139T2C507AA 4139T2C523AA Toner collecting screw Waste toner conveyance unit Toner agitating screw 4139T2C524AA Toner collecting screw Transfer belt Driven roller Toner agitating screw Main motor M1 Waste toner conveyance unit ...

Page 81: ... by the cleaning blade of the photo conductor are conveyed by each of the toner collecting screws into the drum cartridge A Image transfer belt unit Waste toner scraped off by the cleaning blade is collected by the toner collecting screw for transfer belt The waste toner collected by the toner collecting screw is conveyed to the drum cartridge by way of the waste toner conveyance unit 4139to2085e0...

Page 82: ...d if the waste toner reaches an upper limit which allows the machine to determine that there is a waste toner near full condition To prevent false detection the drum cartridge is provided with the toner agitating screw that ensures that the waste toner is evenly stored B Waste toner full detection control The machine determines that there is a waste toner full condition when 200 images are reached...

Page 83: ...ation ver 1 0 July 2006 52 magicolor 2490MF Composition Operation 15 Paper feed section 15 1 Composition 4139T2C551AA 4139T2C508AA 4139T2C525AA Lower Feeder Unit Tray1 paper empty sensor PS9 Tray1 paper pick up solenoid SD1 Pick up roller ...

Page 84: ...re selected according to the type of paper 4139T2C527AA Main motor M1 Pick up roller Tray1 paper pick up solenoid SD1 Paper pick up clutch Main Motor M1 C TOD Tray1 Paper Pick up Solenoid SD1 Registration Roller Solenoid SD2 Print Start Signal Registration Sensor PS1 Belt Positioning Sensor PS4 C TOD C TOD Top of Data CD Print Start signal for cyan Exit Sensor PS7 4139T2E573AA Media type Main moto...

Page 85: ...oid is energized drive from the main motor is trans mitted to the pick up roller via the paper pick up clutch The pick up roller is thereby rotated At the same time the lift cam is rotated which raises the paper lift plate This allows the paper to be taken up and fed in by the pick up roller 4139to2089e0 Lift Cam Paper Lift Plate Cam Paper Lift Plate 4139to2101e0 ...

Page 86: ...e of tray1 detecting the paper loaded in the tray When there is paper loaded in the tray the actuator drops into the tray unblocking the sensor light When paper runs out the actuator is raised blocking the sensor light 15 3 6 Paper feed retry function To reduce the number of paper misfeeds detected due to failure to take up and feed in paper properly another paper feed sequence is carried out if t...

Page 87: ...or 2490MF Composition Operation 16 Conveyance section registration roller 16 1 Composition 4139T2C509AA 4139T2C529AA 4139T2C528AA Registration roller OHP sensor PS2 Conveyance roller Registration sensor PS1 Main motor M1 Registration roller solenoid SD2 Registration roller Conveyance roller ...

Page 88: ...eached the conveyance section Conveyance of paper is restarted by synchronizing the paper conveyed with the image Since the conveyance roller and registration roller are synchronized with each other no loop is formed in the paper at the registration roller 4139T2C530AA Registration sensor PS1 Actuator 4139T2E574AA Tray1 Paper Pick up Solenoid SD1 Paper feed sequence started Drive stopped Registrat...

Page 89: ...t is made does not match the results of OHP sensor detection the machine suspends the print cycle and displays a corresponding message on the control panel 16 3 3 Size error detection control To prevent incorrect printed pages the size of the paper being conveyed is detected using the registration sensor The length of the paper is detected based on the value calculated using the period of time tha...

Page 90: ...section 59 magicolor 2490MF Composition Operation 17 Fusing section 17 1 Composition 4139T2C510AA 4139T2C567AA 4139T2C531AA 4139T2C532AA Thermistor Thermostat Exit sensor PS7 Pressure roller Heating roller Heater lamp Cleaning roller Fusing motor M4 ...

Page 91: ... prevent double transferred image or brush effect the difference between the fusing speed and paper transport speed during image transfer is corrected The fusing speed is changed in two steps relative to the system speed either at high speed which is 2 of the system speed or low speed which is 2 5 of the system speed The fusing motor is controlled to achieve this speed change in two steps Fusing M...

Page 92: ... loop sensor is activated blocked 3 While the fusing paper loop sensor remains activated the fusing speed is kept at the high level 4 When the fusing paper loop sensor is deactivated the fusing speed is immediately switched to the low level 5 The sequence of these operations is repeated so that the fusing speed is changed automatically according to the loop length This effectively makes for the di...

Page 93: ...rature setting 169 C b If the temperature humidity sensor detects a temperature of less than 20 C temperature control is performed with the heating roller temperature setting changed to 174 C 2 In standby state Heating roller temperature setting 180 C a If the heating roller temperature is 60 C or less when the warm up cycle is started tem perature control is performed with the heating roller temp...

Page 94: ...he warm up cycle is more than 60 C b Temperature control is performed accord ing to the temperature measured with the temperature humidity sensor For details see 2 color printing 1 sided P 65 2 In standby state Heating roller temperature setting 180 C a If the heating roller temperature is 60 C or less when the warm up cycle is started tem perature control is performed with the heating roller temp...

Page 95: ...onger Machine interior temperature is less than 20 C 170 C Machine interior temperature is 20 C or more 165 C C During print cycle To ensure good fusing performance the set temperature of each roller is varied accord ing to the paper type and environment 1 Monochrome printing Temperature control is changed back to that listed under ordinary environment in the table when the temperature humidity se...

Page 96: ...urs or in the energy saver mode 1 Control start timing The door is opened or a malfunction or paper misfeed occurs A request for energy saver mode is granted 2 Control termination timing All of the following events are canceled door open an error or malfunction that has occurred and energy saver mode Media type Heating roller temperature at the start of warm up cycle Ordinary environment C Tempera...

Page 97: ...d the output level of the CPU of the mechanical control board becomes a HIGH or LOW level and not a pulse output and a predetermined tempera ture or higher is detected a circuit within the mechanical control board turns OFF the relay to shut down the power supply to the heater lamp C Thermostat protection If neither the soft protection nor hard protection can detect an abnormally high tempera ture...

Page 98: ...ol the number of printed pages per minute is established for each paper size A Monochrome ordinary environment B Monochrome low temperature environment The low temperature environment refers to the condition in which the temperature humidity sensor detects a temperature of less than 20 C C Color environment Length Less than 210 mm 210 215 mm 216 256 mm 257 296 mm Width 139 mm or less 14 14 14 14 1...

Page 99: ...er exit section Theory of operation ver 1 0 July 2006 68 magicolor 2490MF Composition Operation 18 Paper exit section 18 1 Composition 4139T2C510AA 4139T2C552AA 4139T2C558AA Exit sensor PS7 Paper exit roller ...

Page 100: ...18 3 1 Exit tray full detection The exit tray is provided with a paper full detection system When the exit tray full sensor is unblocked the corresponding message will be displayed on the control panel 4139T2C557AA Paper exit roller Fusing motor M4 Exit Tray Capacity plain paper 100 sheets 4139T2C553AA Exit tray full sensor PS11 ...

Page 101: ...r output ATVC Described in the section dealing with the transfer section Temperature humidity Sensor TEM HUMS To ensure stabilized image density to ensure good tone reproduction AIDC control Leak detection control AIDC intensity control Reflectance measurement control Control of the maximum amount of toner sticking Laser intensity adjustment control γ correction control IDC Sensor IDC Temperature ...

Page 102: ... is measured using the IDC sensor One measurement is taken for one complete turn of the image transfer belt The measured value is corrected during the laser intensity adjustment control and γ cor rection control 19 2 4 Control of the maximum amount of toner sticking The developing bias setting value is adjusted to keep constant the amount of toner stick ing to the surface of the photo conductor wi...

Page 103: ...e last The power switch is turned OFF and ON or the energy saver mode is canceled after a predetermined number of printed pages have been produced A new drum cartridge or toner cartridge is detected Mode 2 The power switch is turned OFF and ON or the energy saver mode is canceled after a predetermined number of printed pages have been produced Mode 2 AIDC intensity control Reflectance measurement ...

Page 104: ...6 20 Other control 73 magicolor 2490MF Composition Operation 20 Other control 20 1 Fan control 20 1 1 Construction 4139T2C554AA Suction Exhaust Ozone filter Power supply cooling fan motor Ventilation fan motor IR cooling fan motor Exhaust ...

Page 105: ...r any condition other than above Stop conditions In energy saver mode The power supply cooling fan motor develops a malfunction B Ventilation fan motor Full speed condition While the main motor remains energized Stop conditions The lapse of a predetermined period of time after the main motor has been deenergized Stop under any condition other than above Forced stop condition A door is opened a pap...

Page 106: ...peration 20 2 Temperature humidity sensor 20 2 1 Composition The temperature humidity sensor is used to detect the temperature of the inside of the machine It is also used for image stabilization transfer ATVC and fusing temperature control 4139T2C555AA Temperature humidity sensor TEM HUMS ...

Page 107: ...20 Other control Theory of operation ver 1 0 July 2006 76 magicolor 2490MF Composition Operation Blank Page ...

Page 108: ...SERVICE MANUAL 2006 07 Ver 1 0 Auto Document Feeder Unit THEORY OF OPERATION ...

Page 109: ... represents the number of times the revision has been made To indicate clearly a section revised show in the lower outside section of the correspond ing page A number within represents the number of times the revision has been made NOTE Revision marks shown in a page are restricted only to the latest ones with the old ones deleted When a page revised in Ver 2 0 has been changed in Ver 3 0 The revi...

Page 110: ...osition operation 2 Composition 3 3 Drive 4 4 Mechanical operations 5 4 1 Document take up mechanism 5 4 1 1 Document take up mechanism 5 4 1 2 Document separation mechanism 6 4 2 Document transport exit mechanism 7 4 2 1 Document transport mechanism 7 4 2 2 Document exit mechanism 8 4 3 Miscellaneous 9 4 3 1 Document feeder raised lowered position detection mechanism 9 ...

Page 111: ...Auto Document Feeder Unit Outline Composition Operation Theory of operation ver 1 0 July 2006 ii Blank Page ...

Page 112: ...height of 8 mm or less Types of document Possible malfunctions Original that is stapled or clipped Feed failure damage to the original or drive failure due to clip clogging Pasted originals Misfeed broken original or folded paste up edges Book original Feed failure damage to the original or drive failure Original weighing less than 60g m2 or 129g m2 or more Feed failure Torn original Feed failure ...

Page 113: ...sitive paper Edge folded exit failure transport failure Translucent paper Take up failure transport failure Paper immediately after paper exit from the main unit Take up failure transport failure Paper with many punched holes e g loose leaf limited to vertical feeding Multi page feed due to flashes from holes Sheets with 2 to 4 holes Transport failure Sheets two folded or Z folded Transport failur...

Page 114: ...Operation Auto Document Feeder Unit Composition operation 2 Composition 4556T2C505AA 4556T2C509AA 4556T2C507AA Main motor M1 DF control board DFCB Paper feed sensor PS2 Paper leading edge detection sensor PS3 Original detection sensor PS1 Take up roller Pick up roller ...

Page 115: ...3 Drive Theory of operation ver 1 0 July 2006 4 Auto Document Feeder Unit Composition Operation 3 Drive 4556T2C508AA ...

Page 116: ...eder The stopper is lowered in the standby state and raised when the document is taken up and fed in The document stopper is raised and lowered in synchronism with the raising and lower ing motion of the pick up roller The pick up roller and take up roller turn to take up and feed the original properly The pick up roller transports the original up to the take up roller The main motor drives the pi...

Page 117: ... friction on the front side of the paper fed between the take up roller and separator pad is equal to that on the backside of the paper This allows the take up roller to transport the paper Multiple sheet feeding The coefficient of friction between the paper and separator pad is greater than that between sheets of paper This allows only the first sheet of paper to be transported by the take up rol...

Page 118: ...echanism 4 2 1 Document transport mechanism The original that has been taken up blocks the paper feed sensor The transport roller turns to transport the original up to the document scanning position of the printer The main motor drives the transport roller through a gear train 4556T2C503AA Main motor M1 Transport roller Paper feed sensor PS2 ...

Page 119: ...echanism The exit roller turns to feed the original out of the document feeder During this sequence the original blocks the paper leading edge detection sensor and is fed onto the document exit tray The main motor turns the exit roller through a gear train 4556T2C504AA Main motor M1 Exit roller Paper leading edge detection sensor PS3 ...

Page 120: ...nism There is a magnet provided in the document feeder allowing the printer to detect the position of the document feeder whether the document feeder is raised or lowered This magnet attracts the original cover set switch provided on the printer side thus acti vating the sensor The printer will then detect the position of the document feeder 4556T2C510AA Original cover set switch SW4 Magnet ...

Page 121: ...4 Mechanical operations Theory of operation ver 1 0 July 2006 10 Auto Document Feeder Unit Composition Operation Blank Page ...

Page 122: ...SERVICE MANUAL 2006 07 Ver 1 0 Lower Feeder Unit THEORY OF OPERATION ...

Page 123: ... represents the number of times the revision has been made To indicate clearly a section revised show in the lower outside section of the correspond ing page A number within represents the number of times the revision has been made NOTE Revision marks shown in a page are restricted only to the latest ones with the old ones deleted When a page revised in Ver 2 0 has been changed in Ver 3 0 The revi...

Page 124: ...y of operation ver 1 0 July 2006 i CONTENTS Lower feeder unit Outline 1 Product specifications 1 Composition operation 2 Composition 3 3 Drive 4 4 Mechanical operation 5 4 1 Conveyance drive mechanism 5 4 2 Paper empty detection 6 4 3 Tray set detection 7 ...

Page 125: ...Lower Feeder Unit Outline Composition Operation Theory of operation ver 1 0 July 2006 ii Blank Page ...

Page 126: ...r feed cassette Type Front loading type Installation Desk type Document Alignment Center Paper size A4 Letter Paper type Plain paper 60 to 90 g m2 16 to 24 lb Capacity 500 sheets Power requirements DC 24 V 10 supplied from the main unit DC 5 V 5 Max power consumption 12 W Dimensions 495 W 581 D 138 H mm 19 1 2 W 22 3 4 H 5 1 2 D inch Weight 5 0 kg 11 lb Temperature 10 to 35 C 50 to 95 F with a flu...

Page 127: ...1 Product specifications Theory of operation ver 1 0 July 2006 2 Outline Lower Feeder Unit Blank Page ...

Page 128: ...2006 2 Composition 3 Composition Operation Lower Feeder Unit Composition operation 2 Composition 4056T2C509AA 4056T2C501AA 4056T2C502AA PF drive board PFDB Paper empty sensor PS1 Tray set detecting switch SW1 Paper pick up solenoid SD1 ...

Page 129: ...3 Drive Theory of operation ver 1 0 July 2006 4 Lower Feeder Unit Composition Operation 3 Drive 4056T2C510AA ...

Page 130: ...ance drive from main motor is transmitted through a coupling gear from the printer The paper separation mechanism uses separation claws installed in the unit and elastic ity of the paper It ensures that only one sheet of paper is fed in at time The paper pick up solenoid is controlled from the printer side through the PF drive board mounted in the lower feeder unit 4056T2E506AA Paper Pick up Solen...

Page 131: ...ard detects a paper empty condition in the lower feeder unit When there is paper loaded in the lower feeder unit the actuator is raised which unblocks the sensor When there is no paper the actuator drops into the slit in the paper lift plate thus block ing the sensor 4056T2E507AA PF Drive Board PFDB At paper empty condition Under normal condition Paper Empty Sensor PS1 ...

Page 132: ...on The lower feeder unit is provided with a tray set detecting switch that is attached with a segment lever When tray 2 is inserted the switch actuator on the right hand side of tray 2 pushes the lever This turns ON the tray set detecting switch Tray Set Detecting Switch SW1 Switch Actuator Tray 2 Lever OFF ON 4056T2E508AA ...

Page 133: ...4 Mechanical operation Theory of operation ver 1 0 July 2006 8 Lower Feeder Unit Composition Operation Blank Page ...

Page 134: ...SERVICE MANUAL 2006 07 Ver 1 0 Duplex Option THEORY OF OPERATION ...

Page 135: ... represents the number of times the revision has been made To indicate clearly a section revised show in the lower outside section of the correspond ing page A number within represents the number of times the revision has been made NOTE Revision marks shown in a page are restricted only to the latest ones with the old ones deleted When a page revised in Ver 2 0 has been changed in Ver 3 0 The revi...

Page 136: ...aper exit roller drive coupling mechanism 6 4 1 3 Switchback motor control 6 4 2 Transport and duplex paper take up mechanism 7 4 2 1 Transport and duplex paper take up operation 7 4 2 2 Duplex option transport motor control 7 4 2 3 Duplex option loop correction control 7 4 3 2 sided printing method 8 4 3 1 Operations in 2 sided printing with a single sheet of paper resident in the system 8 4 3 2 ...

Page 137: ...Duplex Option Outline Composition Operation Theory of operation ver 1 0 July 2006 ii Blank Page ...

Page 138: ...nit Reversing system Exit roller switchback Conveyance system Rubber roller driven rolls Document alignment Center Paper size A4 Letter Legal Paper type Plain paper 60 to 90 g m2 16 to 24 lb Recycled paper 60 to 90 g m2 16 to 24 lb Power requirements DC 24 V 10 supplied from the main unit DC 5 V 5 supplied from the main unit Max power consumption 42 W Dimensions 370 W 153 D 318 H mm 14 1 2 W 6 D 1...

Page 139: ...1 Product specifications Theory of operation ver 1 0 July 2006 2 Outline Duplex Option Blank Page ...

Page 140: ...ion 2 Composition 4057T2C509AA 4057T2C502AA 4057T2C501AA 4057T2C503AA Transport roller 1 Registration roller Transport roller 2 Cooling fan motor FM1 Reverse motor M2 Transport motor M1 Door sensor PS2 Registration solenoid SD1 Registration roller Paper loop sensor PS1 AD drive board ADDB Transport sensor PS3 ...

Page 141: ...3 Drive Theory of operation ver 1 0 July 2006 4 Duplex Option Composition Operation 3 Drive 4057T2C504AA Reverse motor M2 Transport motor M1 Transport roller 2 Registration roller Transport roller 1 ...

Page 142: ...rations 4 1 Switchback mechanism 4 1 1 Switchback operation The paper exit roller of the main unit is used to subject the 1 sided print to a switchback sequence so that the 1 sided print is to be transported through the duplex option 4057to2507c0 Exit sensor PS7 Feeding the paper into duplex option Paper exit roller ...

Page 143: ...assy of the fusing unit is raised by the lead ing edge of the duplex option lever thereby disconnecting drive from the machine fusing roller The paper exit roller is driven by the duplex reverse motor 4 1 3 Switchback motor control Rotation of the reverse motor is controlled by the signal output from the DF control board 4057to2508c0 Reverse motor M2 Duplex option lever Fusing unit gear assy ...

Page 144: ...motor is controlled by the signals output from the DF control board 4 2 3 Duplex option loop correction control A loop correction mechanism is provided to prevent skew from occurring in the second page The registration solenoid is energized after the lapse of a given period of time after the paper loop sensor has been activated This drives the registration roller When the regis tration roller is d...

Page 145: ... when the FD length is no less than 276 mm no more than 297 mm 2 Operation 1 The first sheet of paper is taken up and fed in from the main unit drawer and the main unit starts the first print cycle to produce the print image of the second page of the original Paper exit roller Operation 2 Immediately before the 1 sided print leaves the paper exit roller the direction of rotation of the paper exit ...

Page 146: ...the original on the other side of the 1 sided print 1 2 Operation 5 While feeding the first 2 sided print out of itself the main unit carries out the first print cycle for the second sheet of paper to produce the print image of the fourth page of the original 1 2 4 Forward Rotation Forward Rotation Backward Rotation Duplex Registration Solenoid SD1 Duolex Transport Motor M1 Duplex Reverse Motor M2...

Page 147: ...rst 1 sided print is transported toward and into the duplex option At the same time the second sheet of paper is taken up and fed into the main unit 4 2 Operation 3 The main unit carries out the first print cycle for the second sheet of paper to produce the print image of the fourth page of the original At the same time the first 1 sided print is transported through the duplex option Operation 4 T...

Page 148: ... sided print for the third sheet is transported toward and into the duplex option At the same time the second sheet of paper is fed into the main unit again 1 4 2 6 3 Operation 7 The main unit carries out the first print cycle for the second sheet of paper to produce the print image of the third page of the original At the same time the first 1 sided print for the third is transported through the ...

Page 149: ...dent in the sys tem 4057T2E508AA Belt Positioning Sensor PS4 Registration Sensor PS1 Exit Sensor PS7 Duplex Reverse Motor M2 Duolex Transport Motor M1 Duplex Registration Solenoid SD1 Duplex Paper Loop Sensor PS1 Forward Rotation Backward Rotation Forward Rotation Forward Rotation Forward Rotation Forward Rotation Backward Rotation Backward Rotation Backward Rotation ...

Page 150: ...ESS TECHNOLOGIES INC Printed in Japan Printed in Japan DD4139 A TE1 DD4139 A TE1 Use of this manual should be strictly supervised to avoid disclosure of confidential information Use of this manual should be strictly supervised to avoid disclosure of confidential information ...

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