I bought a refill kit (black ink) at Fry’s in Manhattan Beach, and followed its instructions for refilling a Lexmark cartridge (along with the instructions in the printer manual for removing and adding a cartridge).
However, as far as the printer and the computer console are concerned, the cartridge is still almost empty, and printed pages I’ve received from the printer are faded and streaked, befitting a nearly-empty cartridge: The printer isn’t acknowledging the new ink. I went back to Fry’s and a senior salesperson told me I’ll need to contact the “manufacturer,” of the Lexmark hardware or of the refill cartridges he didn’t say which. Have I failed to notice–or do–something here? 
All Lexmark will do is tell you that you’ve voided your warranty!
I know that inkjet cartridges are expensive (that’s why the printers themselves are so cheap) but trying to refill them is a waste of time and money. They are not designed to be refilled. The new ink gets clogged by the residue from the old still inside and there are other components inside the cartridges which are not meant to be reused.
I have had good success refilling my black HP cartridges. When I fill mine I have to draw some of the ink through the print head with the supplied syringe. Is there a print head cleaning utility that came with the printer software? That might help.
I do know that the manufacturers are making it more difficult to refill. I have heard that they are installing smart chips on the cartridge to foil refilling.Check out some of the online refillers to see if they offer your particular cartridge.
There are many Fry’s horror stories:
My cousin was sold an off-brand black ink cartridge from Office Max for an HP 640 (he walked in and asked for the right cart, they charged him $30 for an off brand anyway) and it looked like it came from some company that just refills old carts (there was a plastic plug in the top). I don’t know why Office Max would do this, but they done did it. The printer refused to work. I cleaned every inch of it and it still didn’t work. I put in new black and color carts (HP brand) and it worked just fine.
Another story about these refills is my grandparent’s old-but-working Epson color printer. My grandma’s brother bought some cheapy refills and ended up making a complete mess. I had to clean the entire thing out. New carts from Epson worked perfectly.
Lesson: just buy the expensive, correct cartridges. Otherwise, “you get what you pay for.” 
The refill things are just what they seem to be - too good to be true.
I’ve had great experiences using Stratitec refill kits from Sams Club. Quick, easy, no mess. The thing to remember is to refill as soon as you get a “low ink” message. This eliminates the problem of a small amount of ink left in the cartridge drying up and clogging the cartridge. This is especially important if you don’t print very often.
I have the same printer you do. Did you go into the Lexmark program and click on the new cartridge option?
squeeze the cart until you see a drop or two of ink come out a hole that the printer uses. Then run the printer cleaning procedure 4 times or until you get the cart to work right.
btw, you can usually get original carts on ebay.com for a dollar or two for some printers…
From my OP:
Originally posted by Hup the Fool
This may explain my problem! :o
I relented yesterday and bought a new blank cartridge. I had left out about half the instructions printed in the manual for installing a new cartridge–and hadn’t used the on-screen Cartridge instructions at all! I duly installed the new one, wrapping the old one in the new one’s box and a large baggie, and setting it aside. It prints just fine… :o
This may or may not be any help, but: Lexmark is one of the users of cartridges, rather than plain ink tanks – it contains not just the ink reservoir but all or part of the print head itself. If the original is allowed to run dry (or too low), you may end up with air in the works, and no easy way to “prime” it.
I’ve tried ink refills and it would get so clogged, I would have to “print” about 12 pages just to get the ink flowing.