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Key FRU Disassembly
This topic illustrates how to remove and replace key printer Field Replaceable Units (FRUs). Refer to the later topic "FRU List" on page 87 for a list of the printer's FRUs. For more detailed removal/replacement procedures refer to the Phaser 740 Service CDROM.
Printer cabinet
Top cover Hinge frame Conical spring Hinge pin Door Retainer hooks Left side cover
Upper rear cover
Lower rear cover
Multi-purpose tray Left door 740-7-1
Removing cabinet covers
Service Guide
69
Toner level sensor board
Right side covers Rear Front Upper front cover
Front door
Bottom front cover (lift printer to remove)
Lower (lift printer to remove)
740-7-2
Removing cabinet covers
70
Phaser 740 Color Printer
EMI shields
EMI shield
Interconnect wiring shield
740-7-3
Removing the EMI shields Note
Unplug the engine-to-image processor cable from the engine control board.
Service Guide
71
Cartridge selector/eject unit (right door)
1. Disconnect the cartridge selector/eject unit's wiring harness. 2. Counting from the rear of the shaft, remove the third E-ring from the
cartridge selector/eject unit's shaft.
3. Remove the E-ring and keyed bushings from each end of the cartridge
selector/eject unit's shaft.
4. Remove the E-ring second from the front of the cartridge selector/eject
unit's shaft.
Caution
In the next step, do not bend the frame to give additional clearance, as a damaged frame is not replaceable.
5. Unlatch the cartridge selector/eject unit and lower it half-way down to
relieve spring pressure to enable moving the cartridge selector/eject unit's shaft. Slide the shaft forward until it clears the frame. If necessary, tap the rear end of the shaft with a screwdriver handle (no metal) to move it forward.
6. Unhook the tension springs at each end of the shaft from the engine frame.
Note how they fasten to the frame and the right door.
7. Beginning at the rear, remove the cartridge selector/eject unit.
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Phaser 740 Color Printer
Cartridge selector/ eject unit (right door) Remove E-ring and bushing E-ring Keyed bushing Frame Spring Keyed Washer Washer Remove E-ring Disconnect wiring harness
Remove E-ring and bushing Removing the cartridge selector/eject unit
Washer Keyed Washer Spring Frame Keyed bushing E-ring
740-7-7
Service Guide
73
Paper feeder and tray sensor board
Paper tray sensor board
Paper feeder
Back-out stop screws
740-7-4
Removing the paper feeder
74
Phaser 740 Color Printer
Multi-purpose tray pick roller
The multi-purpose pick roller should be replaced whenever the cork separator pad is replaced. The expected life of each is about 30k prints.
1. With a small, narrow, flat-blade screwdriver, carefully release the snap-fit
cover over the multi-purpose tray pick roller. Small access holes allow you to access the five retaining latches.
2. Remove the C-clip retainer from the pick roller shaft. 3. Slide the right-end pick roller retainer on its shaft about 75 mm (3 in.)
towards the front of the printer. You may need to use a small flat-blade screw driver to release the retainers hook from the groove in the shaft it locks into.
4. Slide the pick roller 50 mm (2 in.) on its shaft towards the front of the printer.
Lift up and remove the pick roller.
Latch Pick roller cover Latch Latch Multi-Purpose tray pick roller
Pick roller retainer Retainer groove
740-7-5
Removing the multi-purpose tray pick roller
Service Guide
75
Cork separator pad
The cork separator pad should be replaced whenever the multi-purpose pick roller is replaced. The life is about 30k prints.
1. Grasp the paper guide and push in and down to the bottom of it travel, then
tilt it forward.
2. With a small, narrow, flat-blade screwdriver, reach behind the cork
separator pad and free the two retaining hooks hold the separator pad in place. Note the spring is under tension. Remove the separator pad and spring.
3. Install a new cork separator pad.
Paper guide
Retaining hooks Spring Cork separator pad Paper guide
740-7-6
Removing the cork separator pad
76
Phaser 740 Color Printer
Laser scanner
Shield Laser motor driver board Disconnect wiring harnesses Separate these two wiring harnesses to minimize possible crosstalk Remove three screws Laser scanner
740-7-8
Removing the laser scanner and driver board
Service Guide
77
Power supply
Power supply
Disconnect wiring harnesses Removing the power supply
740-7-9
78
Phaser 740 Color Printer
Main motor Paper feed motor Toner cartridge drive motor
Cleaning board
Toner cartridge drive motor
Paper feed motor
Main motor
Removing the main motor, paper-feed motor, toner cartridge drive motor and cleaning board
Service Guide
79
Toner cartridge drive unit Accumulator belt home position sensor Left door open interlock switch
Toner cartridge drive unit
Home position sensor
Left door-opened interlock switch Interlock 740-7-13 switch cover
Removing the toner cartridge drive unit, home position sensor and the left door interlock switch
80
Phaser 740 Color Printer
Temperature/humidity sensor board
Housing
Lower rear cover
Temperature/humidity sensor board 740-7-14
Removing the temperature/humidity sensor board
Pre-exposure lamp Pre-transfer lamp
Pre-exposure lamp
Pre-transfer lamp
740-7-15
Removing the pre-exposure lamp and pre-transfer lamp
Service Guide
81
Gear train
Gear train Gear train retainer Frame cross member
740-7-18
Removing the gear train
82
Phaser 740 Color Printer
Tray guides
Tray guides
740-7-17
Removing the tray guides
Service Guide
83
Engine control board
Engine control board bracket Engine control board
IC 4 Removing the engine control board Note
740-7-11
Swap NVRAM IC4. IC4 stores print engine parameters and all consumable life counts and the engine print count. Connector CN28, next to IC4 has no corresponding plug.
84
Phaser 740 Color Printer
High-voltage board
Warning Caution
The edges on the inside of the card cage are ragged and sharp and can cut you. When installing the wiring harness retainer, be careful not to press the wiring harness against the tip of a near by screw which will short the harness. The bent edge of the restraint faces the front of the printer. The colored orientation stripe of the front panel wiring harness must be oriented up to properly connect with the connector inside the card cage.
Note
Be careful not to short harness here to nearby screw tip Wiring harnesses
Card cage
Cut hazard here Removing the high-voltage board
High-voltage board
740-7-16
Service Guide
85
Image processor board
NV RAM Boot ROM
Real Time clock
Image processor board
740-7-20
Removing the image processor board Swap components. If you are replacing the image processor board, exchange:
s s s
The Boot ROM (PLCC), requires using a PLCC extraction tool (003-1633-00) The NVRAM chip (DIP) The Real Time Clock module
The components contains important customer-created parameters. The printer may not operate correctly without the components being swapped. Also transfer from the old board to the new board.
s s s
The RAM DIMMs The PhaserShare card (if installed) The SCSI card (if installed) If any DIP switches are mounted on the board, they should be set to "0."
Note
86
Phaser 740 Color Printer