XL300 MAINTENANCE MANUAL Part No. 105880 Rev.
INTRODUCTION The Maintenance Manual is a two-part document. The first part is an introduction to the printer systems and sub-assemblies and theory of operation. The second part provides troubleshooting and scheduled maintenance procedures, including corrective maintenance (removal and replacement) procedures.
Table of Contents 1. GENERAL INFORMATION ..............................……………………. 1.1 Introduction …..…..................................……………………. 1.2 Functional Description .........................……………………. 1.3 Printer Initialization ...........................………………………… 1.4 Printhead Assembly ............................……………………… 1.5 Paper Feeding .................................………………………… 1.6 Paper-Out Detection ............................……………………… 1.7 Bell Operation ................................
.5.3 Operator Panel Removal and Replacement - Figure 4.1 ..........… 4-5 4.5.4 Electronic Chassis Removal and Replacement - Figure 4.2 .....… 4-5 4.5.5 Controller Board Removal and Replacement - Figure 4.2.........… 4-6 4.5.6 Fan Removal and Replacement - Figure 4.2 .................……… 4-6 4.5.7 Power Supply PCB Removal and Replacement - Figure 4.2 ........ 4-7 4.5.8 Line Filter Removal and Replacement – Figure 4.2 …………… 4-9 4.5.9 Transformer Removal and Replacement - Figure 4.2 . . . . . . . . . 4-9 4.5.
List of Illustrations Figure 1.1 Figure 2.1 Figure 2.2 Figure 2.3 Figure 2.4 Figure 3.1 Figure 3.2 Figure 3.3 Figure 3.4 Figure 3.5 Figure 3.6 Figure 4.1 Figure 4.2 Figure 4.3 Figure 4.4 Figure 4.5 Figure 4.6 Figure 4.7 Figure 4.8 Figure 4.9 Figure 4. 10 Figure 4.11 Figure 4.12 Figure 4.13 Figure 4.14 Figure 4.15 Figure 4.16 4-37 Figure 4.17 Figure 4.18 Figure 4.19 Figure A-1 Figure A-2 Spacial Requirements .............................................………. Functional Block Diagram .........................
Chapter 1: GENERAL INFORMATION 1.1: INTRODUCTION The printer is a serial matrix printer capable of producing highly legible copy on forms containing as many as six parts. It is well suited to a variety of applications. The standard ASCII code is employed, and communications may be performed over a serial interface at BAUD rates ranging from 110 to 19,200. A TTL parallel interface is also standard and is compatible with the Centronics convention.
1.3: PRINTER INITIALIZATION At power-on, the printhead is moved slowly left until the carriage reaches the left margin. This is accomplished when a small tab on the carriage engages a photosensor mounted on the left endplate. This position is referred to as the true left margin and all future printhead motion is referenced to this point. Features and forms status which were present in the printer when power was last switched off are loaded from the nonvolatile memory into working storage.
1.6: PAPER-OUT DETECTION A photoelectric sensor is employed to detect the absence of paper. It is attached to the lower-paper guide which is mounted to the bottom side of the platen. The sensor is constructed with an infrared light-emitting diode (ILED) mounted adjacent to a phototransistor. If paper is present, light emitted by the ILED will reflect from the paper and return to the phototransistor. If the paper is removed, no light will be reflected and printing will cease.
1.9: NON-VOLATILE MEMORY A non-volatile memory (NVM) is used to store all programmable printer parameters. Included are such things as forms length, BAUD rate, tab position, communications status, etc. The forms line number is saved in the NVM so that top-of-form position is maintained at all times unless the form is manually moved by the operator. At power-on, if an error is detected, an error code of 6508 will be written into the 4-digit LED display on the control panel.
The NMU relies on the inherent stepper motor operation for position control. It is assumed that the motor faithfully steps once each time it is commanded to do so. This method of control differs from most printers which employ closed loop servo motors and encoder devices. The NMU keeps track of carriage position by counting the number and polarity of steps given to the motor. For reliable position control, it is necessary to ramp the stepper motor from one speed to another.
1.13: CONTROLLER BOARD A single printed circuit board (PCB) contains all the digital and analog circuitry required to operate the printer subsystems and to control the operational protocol. Interface correctors are mounted to the PCB and are accessible via the rear of the printer. Connectors are also provided for the motors, printhead, and sensors. At the heart of the digital circuitry is an Intel 8085A microprocessor (MPU).
PIN ASSIGNMENT 1. Chassis Ground 2. Serial Data Out Asynchronous output data line 3. Serial Data In Asynchronous input data line 7. Signal Ground 11. Data Terminal Ready (DTR) Indicates the printer is open for communication and can accept or transmit data. 20. Data Terminal Ready (DTR) Table 1.1 Serial Interface Connector-Pin Assignment 1.15: CURRENT LOOP INTERFACE OPTION A 20mA current loop interface is an available option.
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1.17: TTL PARALLEL INTERFACE A TTL parallel interface is standard and is mounted on the logic board. It is compatible with most systems which have been designed to operate with Centronics printers. Certain signals found on early Centronics printers are not provided. Should any problems with compatibility arise, contact place of purchase. The interface functions by accepting a 7-bit character code when a datastrobe transistions from high-low, to low-high.
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1.18: PHYSICAL CHARACTERISTICS The printer is packaged in a compact enclosure suitable for use on a desktop, or for mounting to an optional free-standing pedestal. Dimensions for the printer and the pedestal Figure 1.
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Chapter 2: THEORY OF OPERATION 2.1: INTRODUCTION All printer electronic subassemblies, with the exception of the power supply, are contained on one printed circuit board (the controller board). This chapter provides the technician with descriptions of the various circuits contained on the controller board, ie. printhead driver circuit, carriage drive circuit, and an overview of the microprocessor system. 2.
2.3: CHARACTER PRINTING Incoming characters are taken from the communications interface (either serial or parallel) and placed into a FIFO buffer. The characters are then placed into a print buffer to construct the next line to be printed. No printing occurs until all data for that line of print has been received and the printer receives a line terminator (e.g. line-feed, vertical tab, form feed).
T1 is the current rise period, during which the fun power supply voltage is applied to the solenoid to build the current up as quickly as possible. T2 is the slow decay or “free wheeling” period. The supply voltage is removed and current is allowed to re-circulate through the solenoid. T3 is the fast decay or “fly back” period. The sequencing of these periods is controlled by timers. When the solenoids are energized two timers are started.
2.6: CARRIAGE DRIVE Carriage motion is controlled by a stepper motor. The motor is a 1.5 degree two-phase type. The carriage is driven by the motor through a capstan and set of wire cables. The capstan is sized so that one step of the motor corresponds to 1/100 of an inch (the separation of sub-columns at 10 characters per inch). The motor is controlled by the microprocessor which provides step sequencing and timing functions. The motor can be stepped in one phase-on or two-phase-on modes.
Figure 2.4 Carriage Motor Current 2.7: SYSTEM CLAMP The system clamp allows the processor to energize or de-energize the motors by toggling a 1/0 bit. Any time a motor is moved, the 1/0 bit “system ready” must be enabled. This allows step data to be converted to motor current. Therefore, anytime “system ready” is enabled, motors are either stepped by changing step data, or clamped by unchanging step data present at the input of the amplifier. “System ready” also enables the printwire driver circuit.
Chapter 3: Troubleshooting 3.1: Introduction This chapter provides the technician with procedures for troubleshooting the printer. The following table summarized some of the more common problems which may be encountered with the printer. A brief description of the problem is provided with one or more possible causes for each.
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Figure 3.1: Controller Schematic Part No.
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Figure 3.2: Controller Finished Assembly Component Layout Part No.
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Figure 3.3: Power Supply PCB Schematic Part No.
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Figure 3.4: Power Supply PCB Assembly Part No.
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Figure 3.5: Operator Panel PCB Schematics Part No.
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Figure 3.6: Operator Panel PCB Assembly Part No.
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Chapter 4: MAINTENANCE 4.1: INTRODUCTION This chapter provides the technician with scheduled maintenance, corrective maintenance and adjustment and alignment procedures needed to service the printer. 4.2: Recommended Tools and Materials Only a small number of tools are required to perform the maintenance and alignment procedures provided in this chapter. A list of all tools and materials the technician should have available in order to service a printer is given below.
A complete back-up machine for the first 1-25 units installed is recommended beyond the initial 25 units, recommended quantities of spares are as follows: 4.4: Scheduled Maintenance WARNING Make certain printer is disconnected from A.C. power supply before reaching into the printer to perform any cleaning task. CAUTION Do not use any cleaners, solvents, or lubricants on any of the working parts of the printer.
4.4.1: Printhead The printhead should be removed and cleaned approximately every 4-6 months depending on usage. Deterioration of print quality between scheduled cleanings would indicate a need for more frequent cleaning. To remove and clean the printhead proceed as follows: 1. Remove top cover (see Paragraph 4.5.1). 2. Remove printhead (see Paragraph 4.5.24). 3. After removing the printhead and bracket assembly from the carriage, clean the head using a small hard-bristle brush and isopropyl alcohol.
Figure 4.1: Coverset Removal 4.5.1: Top Cover Removal and Replacement - Figure 4.1 I. Raise the access cover (window assembly) (3) to a vertical position and remove it by pulling straight up. 2. Using a long shank Phillips screwdriver, remove the two front comer screws (7) in the bosses. 3. Remove the screw (7) at each end of the keypad support (4). NOTE Failure to remove these two screws before removing the top cover may result in damage to the keypad or the keypad cable. 4.
WARNING Do not operate the printer with the top cover removed. 5. Replace in reverse order. 4.5.2: Bottom Cover Removal and Replacements - Figure 4.1 1. Remove top cover. (See Paragraph 4.5.1). 2. Remove the four screws (15, 16, 17) that secure the printer mechanism to the bottom cover. 3. Lift the keypad support (4) off the support tubes (5) and set it on top of the printer mechanism. 4.
5. Remove electronic chassis (62) from frame. 6. Replace in reverse order. 4.5.5: Controller Board Removal and Replacement - Figure 4.2 1. Remove top cover (see Paragraph 4.5.1). 2. Remove electronic chassis (see Paragraph 4.5.4). 3. Remove ground screw (61). CAUTION Do not over-flex the controller board when removing from standoffs. Do not reach under the controller board with any object and attempt to pry it free from standoffs. 4. Pull the controller board (21) free from each standoff (67).
4.5.7: Power Supply PCB Removal and Replacement - Figure 4.2. 1. Remove top cover (see Paragraph 4.5.1). 2. Remove electronic chassis (see Paragraph 4.5.4). 3. Remove all connectors from power supply PCB (45) 4. Remove two Phillips screws (46) securing power supply PCB (45) to electronic chassis (62). 5. Pull power supply PCB (45) free from standoffs. 6. Replace in reverse order.
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4.5.8: Line Filter Removal and Replacement - Figure 4.2. 1. Remove top cover (see Paragraph 4.5.1). 2. Remove electronic chassis (see Paragraph 4.5.4). 3. Tag line filter leads (32) to ensure correct reconnection then remove leads from transformer (44) and fuse holder (54). 4. Remove two screws (51) securing line filter (32) to electronic chassis and remove line filter. 5. Replace in reverse order. 4.5.9: Transformer Removal and Replacement - Figure 4.2. 1. Remove top cover (see Paragraph 4.5.1).
7. The locking tabs which hold the power switch into the electronic chassis must be removed in order to remove the switch. Use a screwdriver to pry the tabs away from the switch, then use diagonal cutters to cut each tab. 8. A new switch ma then be installed into the electronic chassis by simply pressing it in. 9. Install leads onto replacement switch and replace transformer (44) and line filter (32). 4.5.11: Voltage Switch Removal and Replacement - Figure 4.2 1. Remove top cover (see Paragraph 4.5.
3. Disconnect printhead cable (29) from printhead (172). 4. Remove cable (29) from cable clamps, 5. The cable (29) passes through an opening under the left side of the plate. Pull the cable (29) toward the front of the printer until free of the printer. 6. Replace in reverse order. 4.5.14: Operator Panel Cable Removal and Replacement -Figure 4.2 1. Remove top cover (see Paragraph 4.5.1). 2. Disconnect cable (23) from operator panel (4). 3. Remove bottom cover (see Paragraph 4.5.2 ). 4.
Figure 4.3: Ribbon Advance Cable 4.5.16: Ribbon Advance Mechanism Removal and Replacement - Figure 4.4. 1. Remove top cover (see Paragraph 4.5.1). 2. Remove operator panel (see Paragraph 4.5.3). 3. Remove ribbon advance cables (see Paragraph 4.5.15). 4. Remove two screws (175) securing ribbon advance mechanism (161) to carriage (160) and remove mechanism. 5. Replace in reverse order. 6.
4.5.17: Ribbon Cartridge Spring Clips Removal and Replacement - Figure 4.4. 1. Lift access cover (3). 2. Remove ribbon cartridge. 3. Remove screw (163) securing spring clip (164) to carriage. 4. Replace in reverse order.
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4.5.18: Carriage Drive Cables Removal and Replacement - Figure 4.7 1. Remove top cover. 2. As shown in Figure 4.5, depress the spring idler arm (156) and insert a screwdriver between the lower portion of the arm and the left endplate. This relieves the tension in the carriage drive system and makes it much easier to remove the drive cables. 3. With the carriage moved against the left endplate, loosen the outer nut (74) on the right hand cable stud.
6. Prior to installation of new drive cables, carefully inspect the new pair of cables for damage to either the cable jacket or attached hardware. If any detectable defect is found in the replacement cable jackets, discard the damaged cable and procure an undamaged replacement. CAUTION When handling the drive cables around the printer mechanism, exercise extreme caution to avoid sharp edges of the printer frame. 7.
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10. While holding a slight tension against the cable going onto the drive spool with one hand, use the other hand to rotate the motor shaft in a clockwise direction and wind the cable onto the spool until the carriage rests against the left endplate and all stack is taken up. There should now be approximately 8 1/2 turns of cable on the spool on the end nearest the drive motor. 11.
4.5.19: Spring-loaded Idler Pulley Removal and Replacement - Figure 4.8. 1. Remove top cover (see Paragraph 4.5.1). 2. Remove left carriage drive cable (117) (see Paragraph 4.5.18). 3. Rotate, spool (pulley) (119) on carriage motor clockwise until carriage rests against the right endplate (82). 4. Remove brace from idler arm and allow spring to contract. 5. Remove two screws (131) securing the front right-angle bracket (139) to the left endplate (144) and remove bracket (139). Figure 4.
6. Remove the idler shaft (141) from the remaining right angle bracket (139) and unhook the tensioning spring (129) from the spring bracket (128). 7. Remove spring bracket (128) (if it is to be replaced) by removing two screws (130) securing it to the left endplate (144). 8. Apply a light grease to the shaft prior to installation. 9. Replace in reverse order. 10. See Paragraph 4.5.18 for procedure to replace left carriage drive cable (117). 11.
4.5.21: Left Margin Sensor Removal and Replacement - Figure 4.10 The left margin sensor is an electronic “photo-interrupter.” It contains a light emitting diode (LED) on one side as a light source and a photo-transistor on the other side which acts as an on/off switch. The LED light source turns on the photo-transistor any time the carriage plate sensor flag is away from the sensor and the light travels through unobstructed.
4. Remove the screws (153) that attach the two cable clamps (149) to the left endplate. Slip the clamps off the cable. 5. Remove the two screws (145) that attach the margin sensor (150) to the left endplate (144). Pull the cable and connector through the sensor opening in the endplate. 6. To install the new margin sensor, reverse steps 1 through 5 above. Do not overtighten sensor mounting hardware as it is possible to crack the sensor housing.
Figure 4.11: Carriage Drive Motor 4.5.23: Carriage Drive Spool Removal and Replacement - Figure 4.11 It is possible to replace a damaged or defective drive spool without removal of the carriage motor from the print mechanism. To replace the drive spool: 1. Remove carriage drive cables (see Paragraph 4.5.18). 2. Remove defective spool by loosening the set screw and slipping spool (1 from the motor shaft. 3. Install new drive spool. Refer to Paragraph 4.5.2 1, step 6. 4.
3. Move the carriage (160) to the center of the carriage rails and disconnect the printhead cable connector (29) from the printhead (172). 4. Load paper into the printer to prevent damage to the platen surface or printwires in the event the printhead comes in contact with the platen. 5. Support the printhead (172) while loosening two screws (173) securing the printhead to the carriage (160). 6. Remove the printhead (172) from carriage (160). Avoid snagging the drive cables during removal. 7.
5. Insert a soft cloth through the left endplate hole and under the carriage rail (124). Slide the rail (124) out through the left endplate (144). 6. Remove the Phillips screw (166) and loosen the set screw securing the printhead adjustment lever (167) to the carriage rail (124). 7. Make sure the cloth is still inserted through the left endplate hole. Guide the new rail (124) through the hole, allowing it to slide on the cloth, through the carriage (160) to the right endplate (82).
Figure 4.
5. With the carriage (160) approximately in the center of the mechanism the right end of the upper carriage rail (121) with one hand and the right endplate (82) with the other hand. Pull the shoulder of the rail (121) from the hole in the endplate (82) and continue to pull it up and back in the normal carriage plane until it clears the endplate. 6. The left end of the carriage rail (121) may now be removed from the left endplate (144) and the rear bearing (162) slipped from the bearing carrier. 7.
3. Locate the drive motor cable (28) and cut any wire ties needed to free the cable from the printer harness. 4. Loosen the three screws (195) which attach the motor (194) to the right endplate (82). Slide the motor (194) toward the platen and remove the drive belt (89). 5. Completely remove the three motor attachment screws (195) and the motor (194) may be removed and set aside. 6. Remove the motor pulley (78) from the old drive motor and install on the replacement drive motor.
Figure 4.13: Drive Belt Tension 4.5.30: Paper Drive Shaft Removal and Replacement - Figure 4.14. 1. Remove top cover (see Paragraph 4.5.1). 2. Loosen set screws in drive shaft pulley (90) and motor pulley (78) an, simultaneously remove both pulleys and drive belt (89). 3. Remove the bearing retainer (83) from the right endplate (82). Grasp the drive shaft (188) with one hand and push it toward the right endplate (82) while restraining the endplate with the remaining hand.
6. Slide the shaft (188) through the right endplate (82) and through both tractors. Be sure that the alignment marks on each tractor are matched on the same side of the square drive shaft (188). See Figure 4.14. 7. Complete the installation by reversing steps 1 through 3 above. 8. Set proper tension in drive belt as shown in Figure 4.13. 4.5-31: Drive Shaft Bearings Removal and Replacement - Figure 4.14. 1. Remove top cover (see Paragraph 4.5.1). 2. Remove drive shaft (see Paragraph 4.5.30). 3.
6. The idler shaft (187) may now be slipped from the tractors and set aside. 7. To install the replacement shaft, reverse steps 1 through 5 above. Be sure to install new push-on retainers (80) in step 2.
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4.5.33: Platen Removal and Replacement - Figure 4.16. 1. Remove top cover (see Paragraph 4.5.1) 2. Remove electronic chassis (see Paragraph 4.5.4). 3. Remove printhead (see Paragraph 4.5.23). 4. Remove absorber panel retainers (180, 189). 5. Remove absorber panel (186). 6. Remove three screws (184) securing platen (I 85) to lower paper guide (190). 7. Remove four screws (15, 16, 17) securing left and right endplate (144, 82) to enclosure base. 8.
4.5.34: Printhead to Platen Gap Alignment – Figure - 4.15. Platen alignment must be done with great care to achieve maximum print quality and printhead performance. Care must be exercised to avoid damage to the platen surface and printwires while setting the printhead-to-platen gap. 1. Push the printhead adjustment lever toward the platen into the first detent position. 2. Tighten the platen bolts (92) to where the platen can still move but will stay where repositioned. 3.
Figure 4.15: Printhead to Platen Gap Alignment 4.5.35: Lower Paper Guide/Paper Out Sensor Removal a Replacement - Figure 4.16 1. Remove top cover (see Paragraph 4.5.1). 2. Remove electronic chassis (see Paragraph 4.5.4). 3. Remove three screws (184) securing lower paper guide (190) to platen (185). 4. Remove four screws (15, 16, 17) securing printer mechanism to bottom cover (2) and lift rear of printer mechanism enough to remove lower paper guide (190). 5. Replace in reverse order. 6.
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APPENDIX A This section provides updated schematics for the Main Controller Board (Figure A-1) Part No.
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Figure A.2: Controller Board Assembly Part No.
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