HP Designjet 2500.3500cp Printer series - Manual (Page 209)

Maintaining Your Printer
Lens Maintenance
10-3
Lens Maintenance
The optical sensor on the printhead carriage has a lens cover to protect if from ink
aerosol and other contaminants. The lens cover is located on the lower right side of
the carriage.
Over time, this lens cover will get dirty and need to be replaced. When the printer
detects that the lens cover is dirty, it will display the message:
You should replace the lens cover to prevent any problems with printer operations
due to the optical sensor. Replacement lens covers are provided with your printer
and are stored inside the right door of the printer. You may replace the lens cover
immediately when you see the message or wait until the next time you need to
replace an ink system.
C4704151
Lens Cover
C4704034
STATUS
Lens maintenance