Lexmark Optra Color 1200, Service Manual

Page: 32 / 245

General Information
1-21
5050-001
Transfer Belt
The positive-charged absorption roller charges the paper as it enters
the transfer belt. The belt rotates at the same speed as the
photoconductor drum.Toner is transferred to the paper in the order of
magenta, cyan, yellow, and black. As the paper passes each
photoconductor drum, the static from the transfer belt pulls toner
away from the drum. A little waste toner sticks to the transfer belt as
it passes the drum. This toner is scraped off and collected in the
transfer belt waste toner bottle.
Temperature changes can affect the registration of colors. To
compensate for these changes the temperature of the belt drive
roller is monitored and the timing of the LED head writing is adjusted
accordingly.
The transfer belt unit should be replaced approximately every
100,000 pages. When you replace a transfer belt, you must set the
thermistor resistance settings for temperature control. You must also
make the print adjustments.
There are two printhead adjustments; the margin adjustment and
the color image registration adjustment. Make these adjustments in
the service mode.
The length of the transfer belt is about 760 mm, and the width is
about 320 mm. The belt is conductive and has no seams. Be careful
not to scratch the belt or leave fingerprints on it when you replace
the assembly. If toner remains on the belt in a scratch or on a finger
print, it will create dirty spots on the back side of the paper. If you do
find a stain on the belt, wipe it off with a dry cloth or alcohol.