An inkjet printer works by heating a very small amount of ink, which is then jetted onto the paper. When the low ink warning light glows, it's time to refill or change your cartridge. It's a great idea to keep a spare refilled so that you can keep on printing without pausing to refill. Refill your cartridge when it is convenient for you. Keep your cartridge in an airtight plastic bag for maximum re-use.
Chances are that the ink passages have become clogged with dry ink.
Try blotting the bottom of your cartridge on a dampened paper towel. If this does not clear up the problem, your cartridge may be unable to accept a refill. In this case, do not throw your cartridge away. Click here for information on Recycling My Original Cartridge or ask your Retailer about Recycling. Keep the refill kit for your next cartridge.