Lexmark 3600-4600 stops at 34% when trying to print a test page. Color ink is low, but I only want black in any event.

Make sure that you are inserting only genuine Lexmark cartridges in your printer. Removing then re-inserting the color cartridge into the printer is a quick to minor cartridge communication issues.
Make sure that your color cartridge still has substantial ink level for printing using the Lexmark Solution Center software on your computer.
Click Start > Programs > Lexmark X74-X75 > Lexmark X74-X75 Solution Center. Check the ink levels.
If color ink level is still good, then it probably just needs some cleaning. Print quality issues can be due to dirty or clogged print cartridge nozzles. From the Maintenance tab in the Lexmark X74-X75 Solution Center, click Clean print nozzles to fix horizontal streaks. Your printer will then print a test page. Try to print a color page again to verify that the problem with the blue color is fixed.
If the problem continues, try to insert a different known working color cartridge to identify if it's a faulty cartridge issue.

You dont both inks are used at the same time so if you are getting nothing try running a test page that has color on it to make sure that you have color ink . if it prints in color that way that tells you that there is no "switch" to use color to print black text you will need to replace the black ink cartridge

For 34 Short Paper error, reseat the tray guides and make sure it is set properly. Also, set the correct settings in the computer. For blank pages, always double-check the paper settings and again the settings in the computer. For not printing black, print the Print Quality page and see what color is not printed or not showing. If Print Quality shows black, try printing any document from any application in the computer. Check if you still have the problem. If problem is not resolved, leave a comment so I can get back to this.

You may clean the cartridge by following the steps given below:

1. Remove the cartridge or cartridges from the printer.
2. Get a damp paper towel.
3. Set the ink cartridge right side up on the damp paper towel so that the ink nozzles are against the towel and hold the cartridge in this position for about 15 seconds.
4. Now wipe the print head (on the bottom where the ink comes out) across in one direction only (left to right) until it looks clean.
5. Next dab the cartridge on the towel to make sure that the ink is flowing.
6. Snap the cartridges back into the printer.

Next, I'd like you to attempt this printer self-test by following the steps given below:

1. Disconnect the power cord from the back of the printer.
2. Press and hold the button on the printer panel.
3. Reconnect the power cord and keep holding the button on the printer panel until the printer starts to pull paper.
4. The printer should now print a test page. Please note that the test is continuous. To stop the test, disconnect the power cord.

The self-test should at least print out a set of either black or color bars, if not both (if you have a printer with both color and black installed simultaneously). Should this test fail, try it again without cartridges installed. If the self-test still fails to take paper in and make sounds like the carrier is moving across the paper, this is a hardware issue, and the printer will require service. If the self-test completes without any cartridges installed, run the self-test again with only the color cartridge installed. (If you have both black and color cartridges, after this test, run the test again with just the black cartridge installed.) If you find that either cartridge causes the self-test to fail, please let us know.

If the self-test prints, but has lines or smudges or other print quality issues, let us know.

have you installed the cartridge correctly??? make sure you did

try to print a few pages, to get the ink going.

try test pages, try the aligning procedures as well.

Okay if your using windows OS go to control panel , then printer and fax icon open it you will see Lexmark printer series listed right click on it and go to printing preference tab ,uncheck print all documents in black and white click okay and then try to print....

Good luck...

Try to  print a test page first. To print a test page press and hold the bottons power and cancel together. The test page will show you the amount of ink left in the cartridges.  If the black ink color bar is not visible in  the, than it will mean that the ink is low or depleted. Try a new genuine HP ink cartridge. It should help you.

Unfortunately the printer wont print unless there is ink in both cartridges

Even with out the Black cartridge installed the X1240 should use the color cart to make a "composite" black. I would suggest calling Technical support to troubleshoot that issue ad get you to test the cart itself

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.