Brother 5250DN Troubleshooting

[htmlmasterdave]

I've been really happy with this printer until today when I tried to print some documents and little dots were printed down each page every few inches in a line. I tried cleaning? the toner cartridge by taking it out and sliding the little blue tab back and forth, but it didn't seem to help.

Has anyone else had this problem or heard about it? When I search on google it's hard to find results since the word dot brings up technical articles about laser printers/dot matrix

Thanks