HP Designjet L25500 Printer Series - Maintenance and troubleshooting guide (second edition)

Clean (recover) the printheads
To clean the printheads (which often enables them to recover from problems), go to the printer's front panel
and select the
icon, then select Image quality maintenance > Clean printheads. Specify which printheads
you would like to clean. You can clean all of the printheads or only some of them. Select from these options:
●
Print test plot
●
Clean all
●
Clean LC-C
●
Clean Y-MK
●
Clean LM-M
Cleaning all printheads takes about 5 minutes. Cleaning any two printheads takes about 3 minutes.
NOTE: Cleaning all printheads uses more ink than cleaning a single pair.
Clean the substrate-advance sensor window
The substrate-advance sensor is the very small rectangular window (less than 1 square centimeter in size)
close to the third pinchwheel from the right.
HP recommends that you clean the substrate-advance sensor window whenever you clean the print platen
and if you are experiencing print quality issues.
1. Unload the substrate by using the front panel procedure. See the User's guide.
2. Turn off the printer and wait until it has cooled down.
3. Wipe the sensor with one of the cotton swabs provided in the User Maintenance Kit, slightly dampened
with isopropyl alcohol, to remove dried ink.
If the sensor window is heavily coated with dried ink, you may need to apply some pressure while
wiping, helping the cotton to absorb the ink. Continue cleaning with fresh swabs until the cotton stays
clean and the sensor window looks clean. When reflecting ambient light, a clean sensor shows a blue-
colored reflection that should extend uniformly across its whole surface. You can see this reflection by
moving closer and slightly changing your angle of view.
4. Remove the isopropyl alcohol and the cotton swabs from the vicinity of the printer.
5. Wait three or four minutes to let the alcohol evaporate, before turning on the printer and reloading the
substrate.
18 Chapter 4 Hardware maintenance ENWW