Lexmark T650 Series Service Manual

Diagnostic aids 3-79
4062-XXX
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Charge
The Charge Roll places a uniform negative electrostatic charge on the surface of the drum. The drum surface
is made of a photoconductive material that holds an electrical charge as long as the drum remains in darkness.
Light striking the drum discharges the surface charge.
Exposure
The Printhead generates a beam of laser light. Image data received from the system card assembly modulates
this beam, turning it on and off according to image information that is received from the host computer and
software.
Through the use of a series of rotating and stationary mirrors within the Printhead, the beam scans the
negative charged drum surface. Whenever the print controller sends a command to print a black pixel, the
laser switches on long enough to shine onto the drum at a single pixel point. That point is now discharged and
slightly less negative than the surrounding negative charge. The less negative areas are considered positive.
HVPS
(-VDC)
(-VDC)
Ground
Conductive Tube
Photoconductive
Surface
0V
-VDC value
DRUM
Drum Surface
Voltage
Drum Surface
Image
Ground
Charge roll

Lexmark T650 Series Specifications

General

Print Technology	Monochrome Laser
Print Speed	Up to 45 ppm
Print Resolution	1200 x 1200 dpi
Monthly Duty Cycle	Up to 200, 000 pages
Standard Output Capacity	250 sheets
Processor Speed	500 MHz
Connectivity	USB, Ethernet
Maximum Paper Size	8.5 x 14 inches
Operating System Compatibility	Windows, Mac OS, Linux
Memory	128 MB, expandable to 640 MB
Standard Input Capacity	650 sheets