Frequently Asked Questions

How do I make sure I am ordering the right cartridge for the M603n?

Match the code, not the description. The M603n takes the CE390X high-yield cartridge, equally well known by its short name 90X. If either code appears on the label of the cartridge you are replacing, this listing is the correct one.

Our M603n runs across shifts. How should we handle cartridge changes?

Keep one sealed spare at the printer and make the swap a two-minute, any-shift task: top cover up, old cartridge out, sealing strip off the new CE390X, slide in, close. Because the rating is 24,000 pages, changes are rare events — the main discipline is simply never letting the shelf spare be used without ordering its replacement.

Does an around-the-clock duty cycle shorten cartridge life?

The cartridge counts pages, not hours. It delivers its 24,000 pages whether they are printed in one intense week or spread over a quarter; what heavy use changes is how soon you reach the total, which is precisely why the high-yield 90X suits this machine better than a standard-fill unit.

What does the printer do when the cartridge finally runs dry?

It stops and reports the supply as empty rather than printing blank pages into a job. Output quality gives earlier notice — greying text and thinning solids — so in practice the cartridge is normally changed on the fade, before the hard stop arrives.

Can one spare cover several different printers here?

Yes. The LaserJet Enterprise 600 M603n uses the same CE390X as the M601 and M602 printers and the M4555 multifunction series, so a single spare policy works across the whole monochrome fleet.

What cover is included with this cartridge?

A 1-year warranty and 1-year free returns. If the unit is damaged on arrival or gives up far short of its rated life, it is replaced or refunded, and the support team is available Monday through Friday, 9 AM to 5 PM CST.

About This CE390X (90X) Cartridge — M603n Listing

This page is the supply listing for the M603n, the networked high-speed model of the 600 series: one CE390X (90X) black cartridge, rated at 24,000 pages, at $58.64. It is supplied sealed and ready for immediate fitting, and it doubles as the spare for every other 600-series and M4555 machine on the same site. Orders ship from warehouses in IL, PA, GA and CA — the shipping & returns page sets out delivery and returns, and the rest of the family's supplies are under HP.