HP Designjet T1100 MFP series - Manual (Page 192)

You must remove the printhead, see Remove a printhead on page 124 , and using a lint free cloth, clean
the bottom of the printhead until the residue is removed.
Clean the printhead drop detector
The printhead drop detector is a sensor that detects which nozzles on the printheads are not printing in
order to substitute them for good printing nozzles. If particles, such as fibers, hair, or paper pieces, block
the sensor print-quality is affected.
When the front panel displays a warning message that the clean process is needed, you are
recommended to clean the printhead drop detector. If you do not clean the printhead drop detector
immediately, the printer continues working normally, however, the front panel display continues to show
the warning.
CAUTION: Wear gloves to avoid getting ink on your hands.
1. Turn off the printer at the front panel.
180 Chapter 16 Troubleshooting ink cartridge and printhead issues ENWW
Ink system issues