HP LaserJet Enterprise 600 Printer M603 series - Manual (Page 211)

Type of print cartridge Steps to resolve the problem
Refilled or remanufactured print
cartridge Hewlett-Packard Company cannot recommend the use of non-HP supplies, either
new or remanufactured. Because they are not HP products, HP cannot influence
their design or control their quality. If you are using a refilled or remanufactured
print cartridge and are not satisfied with the print quality, replace the cartridge with
a genuine HP cartridge.
Genuine HP print cartridge 1. The product control panel or the supplies status page indicates Very Low
status when the cartridge has reached the end of its designated life. Replace
the print cartridge if print quality is no longer acceptable.
2. Visually inspect the print cartridge for damage. See the instructions that follow.
Replace the print cartridge if necessary.
3. If printed pages have marks that repeat several times at the same distance
apart, print a cleaning page. If this does not solve the problem, use the
repeating defects information in this document to identify the cause of the
problem.
ENWW Improve print quality 195