Guys If you have gaps in your nozzle check only run the cleaner cycle once or twice at the most. Think about it: If the nozzles are blocked with dried ink, dumping a bunch of ink in there will not clear it. It only makes thing worse, and then that ink dries.
The best thing to do is to get some print head cleaning solution from eBay or make your own out of distilled water, 99% alcohol and a few drops of dish soap. Look online for the exact recipe. Soak a paper towel and fold it to fit in the channel the print head glides above. Start the printer cartridge replacement but don't remove them. Unplug your printer from the outlet once the printhead moves freely from its parked position. Work the paper towel soaked with the cleaning solution under the print head. The trick is to make sure you are completely under all the nozzles. Now here's the hardest part: You have to wait. I cleared a WF4590 that was completely clogged from sitting and I used it until it died from an unrelated scanner bed error. I think I let it sit for a week on that soaked towel.
You will need surgical gloves because you will be grabbing an ink soaked soggy paper towel when you are done. Once you remove the soggy towel, place a dry paper towel in the same channel and slide the print head over it a few times. You will have to run a nozzle check to see if you still have gaps. Here's the thing though: you will still have gaps after clearing the head because there are several micro pieces of dried ink. In order to clear these you need 2 things: extra ink and paper; and a word doc of large blocks of color in the main colors of your cartridges: I use a single page of solid black for black and I use a single page of 3 blocks of color: one Cyan, one Magenta and one Yellow and I space them so that the 3 are the same size and they take up a whole page together.
Print 10 - 20 pages of the patterns you need to clear. If it's multiple color inks giving you trouble you can just print the color page if it's just black you can print the black page. If it's only one color you can change the other colors to the color you need (print less pages, usually there's less color ink than black).
Let me explain what this does. It's very similar to a maintenance head cleaning cycle with one major difference: The ink you are dumping in there is not just sitting there. It gets used and won't add to the problem. As you print, the wet ink will gradually start to break up the little dried particles and eventually you will clear that nasty clog. Most times a few gaps are a sign of air in the lines and a few full pages of text or photos can clear that up.
I've restored several used printers doing this and it has allowed me to buy higher end printers at a much lower cost because someone thinks it is trash. The 4590 I bought for $45 It sat for a while because someone dropped something in it and it was blocking paper from the feed and they tried to take it apart and fix it but couldn't. I got the blockage out and used my trusty print cleaning method outlined above and it worked for several years.