All of a sudden the printer stopped printing in color. We changed the lowest color cartridge (still has 10% on it, according to the online page for the printer), and that didn't help. The online page for the printer indicates that "PCL Color Mode" is set to Black - could that be the problem? We used the Menu key on the printer to reset the printer to default settings, and that didn't help.

Your color cartridge does n't print well
in order to have a success alignement
check if the expire date has pass

you need to replace the color cartridge or refill it
by this easy method

Step 1:-
First of all go to the printer--> Press setup button on it --> use the Arrow keys --> choose the tools option --> now choose the option Print a test page--> If the test page prints fine--> The printer is fine. No problem in the printer.
Else take out the cartridges and clean it with a lint free cloth. ( Remember when cleaning the cartridges DO not touch the nozzel of the cartridge. Just clean the out side of the cartridge nozzel.)
Step 2:-
Try to change the color of the font on the document you are printing and then try printing. You will get to know if it is actually printing or not. If it is not printing in color also then try this ...!
Click on start--> go to control panel--> go to printers and faxes or printers option and then right click on the printer and choose properties option. Click on the print a test page button.--> Check if it works.
Let me know if it works..!

Use only original ink cartriges, the non original has ink normaly is not for you printer, and you wast your money and damage the printer print-head

Unfortunately it is all true.
Personally I would stay away from Lexmark, I am a Canon fan, the MP520 looks real nice, but it's personal choice at the end of the day.

You can just click the print button and the printing will begin, I was having the same problem.

I have two problems. Either it won't accept a print job or when it is printing it stops when it is going through the job intermittently. Like for an hour it won't continue then all of a sudden it prints one page then a half hour later another page etc. It is so frustrating.

So it never worked?, return it, run the utility first that is on either the disk or the website

You are using HP's cartridge with the smallest output . So if you are printing 80 pages of text, you will have a problem by the time you reach 95 or 100 pages. If you are printing in color, you only have 1ml/color. Meaning 3 colors. But in order to print a red, it will combine a magenta and yellow to product 1 color. So 3 colors doesn't mean 3 ml worth of colors. Effectively you may only be able to print 10-20 pages of color then your cartridge is empty. The black cartridge has about 4-5ml of ink. So if you print a lot I suggest you get another printer.

I just got off the HP help line.  After changing my black ink cartridge a test page was printing each time I turned the machine on.  This is very costly, in both time and ink as the cartridges themselves for this machine hold very little ink.  I tried to learn from HP tech how to turn off the test-print while keeping my color cartridge empty.  It turns out that you cant do it.  HP requires you to keep buying and using cartridges whether you need them or not.If you buy the color ink it will use it up in its testings.  And if you dont buy the color cartridge it will use up your black ink by printing the test each time you turn on the printer.  The printer was inexpensive sure, but I'm paying for it in wasted ink. 

Sounds like the color cartridge is overheating. Could be defective, ESPECIALLY if it not an original Hp BRAND NEW cartridge. Change out the color cartridge and see what happens. Each tiny little nozzle has its own heating element. Electronics monitor the temperature. Will stop the printing until the temperature comes back to an acceptable range. Ed