As would be assumed, an empty ink tank can cause the printer to print light or completely blank. However, this can also be caused by the cartridge if the print head had become clogged with dry ink. This can usually be cleared by using the utility in the printer driver to clean the print head. This is accomplished from the Print dialog box by selecting the 'Utility' button and check the 'Clean ink cartridge before printing' option. This may need to be done five or six times to clear a severely clogged print head.
If cleaning the print head does not resolve the problem, it is possible that the print head is bad and needs to be replaced. The print head cartridge is designed to be used through several changes of ink tanks, however as print quality degrades, the cartridge should also be replaced.
One of the worst things you can do to an ink jet printer is to allow it to go for extended periods of time without use. Without regular use, the small holes that make up the print head become clogged with dried ink. This is one of the major causes the symptoms we are discussing here.
Note: It is possible for the ink tanks and cartridge to be good and have the printer go through the motions of printing and put no ink on the page due to a failure in the printer. However, this is very rare and should only be considered after troubleshooting the cartridge/ink tank as described above.