Remove the cartridge, gently move it back and forth two or three times, and then replace it. Do this every time you get the warning light -- if you still get the warning light when you've replaced the cartridge, you know it's time to get a new one.
Why? Because drums have to be replaced a lot less often than cartridges. For example, the drum for the Brother HL-5140 printer has a typical yield of about 20,000 pages -- a lot less than the toner cartridge's yield of 3,500. So printers with separate drums can be cheaper in the long run.
What is that? That is the number of pages that a typical ink or toner cartridge may be expected to produce. Most manufacturers estimate their yields based on coverage of about 4 or 5 percent -- in other words, about 4 or 5 percent of the printed page will actually have ink on it. So a toner cartridge that has a yield of 3,500 based on 5 percent coverage should be expected to print out about 3,500 pages, assuming that each page has about 5 percent of its surface covered by the ink.
This means, of course, that if you tend to print pages that have a great deal of text on them, or that use images, or that use a great deal of bold lettering -- your results will vary greatly.
For example, take a typical inkjet printer like the Brother HL-5140, which costs about $200. A Brother toner cartridge that yields (according to the manufacturer) about 3,500 pages runs about $71. The printer drum, which has a yield of 20,000 (so it should last you quite a long time), costs about $140.
Unfortunately, there are few independent sources that can tell you the true yield for each printer out there. As a result, we have to rely on the manufacturers' figures. But even using those as a guide, you can figure out which printers will cost more in the long run.


