How to fix 946 Dell All in One Printer?

This printer has been used very little; is 2-3 years old perhaps. Hadn't used all summer, then it started printing in very small print, then just quit printing altogether. Computer screen shows it printing as normal, it processes a sheet of paper just as though it is printing, but comes out clean. If I run a test print it releases a bit of color but nothing like a test print pattern. It did collect alot of dust over the summer (no cover) but would that cause it not to print? I finally put it in a box and bought myself a cheaper Canon printer for now. Anyone know what to try?