This printer suck due to it's ink cartridge situaton

[kimayo]

If I had known that if one of the cartridges on this printer was low or out that I could not print in black (even though the black cartridge if full) I would have never purchased this. I will never buy one like it again.

[Bob_Headrick]

Please read this post then provide some details.  What printer model? 

There are generally a few different type of inkjet printers - those like the Deskjet 6940 that have printheads and ink supplies integrated together are called Integrated Print Head (IPH) printers.

Another style has separate individual ink supplies and printheads.  This style has printheads that may be permanent and non-replaceable, or they may be replaceable after some number of ink supplies.  These are called Individual Ink Cartridge (IIC) printers.   An example is the Photosmart C7280, which has permanent non-replaceable printheads.

Most IPH printers will happily print with one (or even both) cartridges low on ink or empty.  Recent models will often allow printing even if one of the cartridges is removed completely, switching automatically to "reserve mode" or "ink backup mode". 

IIC printers have long life printheads and generally have plumbing to connect the ink supplies to the printheads.  These printers (whether from HP or other manufacturers) generally require ink available in all colors to prevent air bubbles in the plumbing ar printhead.  Some ink is also required to keep the nozzles from clogging.  Even in the case of printing black only the color printheads are waving around in the air and may dry out.  Some ink is required to keep the printhead from drying out.

The document here has some information on how ink is used.

[asdfasdf123]

Agreed!  HP really has HP's best interest in mind, not the comsumer's.

I have a HP 5510.  I have the same infuriating problem that I can't print at all if one of the ink cartridges is empty.  Well, I'm no dummy either and tried to get to the root of the problem.  Turns out, there are not really sensors in the cartridge to determine when the ink is full/low/empty (I sawed into one of the cartridges to see).  However, if a cartridge is out of warrenty, the printer (or HP, I haven't looked into whether a networked/online printer is sending info to the HP servers) assumes the cartridge was refilled.  So, regardless of how one uses the printer, HP will require you to buy 4 new cartridges every 2 years.  From the standpoint of a revenue stream, genius (until the consumers find out).  From a consumer standpoint, a real d*ck move.  

Don't believe me?  Check the expiration/warranty date on the bottom of the cartridge and wait for things to go bad just after it.  I'm not joking.  I tried to print for the first time in a few weeks.  Now, my claims my yellow cartridge is non-HP and won't let me print anything although it is a true HP cartridge. Go figure, the warranty printed into the bottom of  cartridge was 8-19-2015.  Shocking, coincidence, I don't think so.

When I purchase another printer (and it won't be HP), I want to be able to use it to fit my needs, not that of the company wishing to reign in another source of revenue.

Goodbuy 5510 and so long HP.  Not thrilled.