Lexmark X4650 InkJet Printer black prints fuzzy. Color is fine, but the black appears out of focus.

Make sure your Adobe application is updated.
Try to update your printer driver as well. Please visit the Lexmark website to download and install the Lexmark X4650 Printer Driver on your computer. Select your operating system > download and execute the file.
Once the update is complete, try to print a PDF file again to verify that the problem is fixed.

Check to see if the cartridge is clogged or running out of ink.

That could be a spooler problem. Make sure the print spooler service on your Windows computer is running. (How to Restart or Reset the Print Spooler in Windows). After following the steps in the article, try to print again.

The Lexmark manual says: Remove the tape from the back and bottom of the color cartridge, insert the cartridge in the right carrier, and then close the color cartridge carrier lid. See pic below...

Some of the ink-jets that shoot the ink onto the paper are clogged.

Use the Lexmark software for the printer to run a few "print-head-cleaning" cycles, to try to unclog it.

Hello. The only common cartridge the X4650 and the X4690 uses is the #31 photo color print cartridge. Other cartridges for the printers are non-interchangeable. For your reference, you can click on this links to the Lexmark website. http://bit.ly/asi8dB and http://bit.ly/bvNeOa . First link shows you compatible cartridges for Lexmark X4650 and the second link is for Lexmark X4690. Hope this helps.

I own a Cartridge World ink refilling store and I can't refill the Lexmark 36 and 37 cartridges. Your printer deactivates the electronics on this cartridge when the ink levels get low. Your printer needs a black and a color cartridge with functioning electronics to print. I NEVER recommend Lexmark printers. They are poorly made, don't accept refills easily, and have the most expensive ink across manufacturers and it is designed to clog your cartridge unless you use it quickly. If you keep this machine you are stuck buying Lexmark brand ink (the return program cartridges are a little cheaper though).

update the drivers from HP webbsite

Well you can do this in the print setup under te color option but you must have color cartridges present anyhow its just the way the system mixes. It ca nbe done tho trust me. But you do want to have color in there because the printer will not go without it. when the black ink runs out it uses color to mix.

Btw, I’m available to help over the phone in case u need at https://www.6ya.com/expert/edwy_1a56970cf1ea4620

is u r catrige original one or fake