I have a Hp Laserjet 3030 all-in-one and it just started printing almost solid grey over the whole page. I tried changing resolutions and other settings, ran the printer's own cleaning cycle a couple times, nothing changed. Even on draft mode it still covers the page. It's not perfectly solid, more like horizontal banding but it covers about 85% of the page or more in grey.
Since the HP 12a drums have no functions for physical cleaning, I replaced the drum entirely, put in a brand new HP 12a. Made a test print, and it has the SAME problem but now WORSE than before! The coverage is thicker and the toner darker across the page with more visible banding.
Here is a scan of the page that printed after replacing the drum:
Is there a transfer wire or cleaning shield or something on the inside that needs cleaning? Not sure where to start.
Thanks for any tips!