Lexmark MX721 User Manual page 179

Maintaining the printer
2
Remove the toner cartridge.
3
Remove the used imaging unit.
4
Unpack the new imaging unit, and then shake it to redistribute the toner.
Warning—Potential Damage: Do not expose the imaging unit to direct light for more than 10 minutes.
Extended exposure to light may cause print quality problems.
Warning—Potential Damage: Do not touch the photoconductor drum. Doing so may affect the quality of
future print jobs.
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