Patchy laser printing

[will_]

What would cause an HP LaserJet 3052 to do this? It's supposed to be 50% grey.

I've tried giving the toner cartridge a shake but it hasn't helped. It's a brand new (third party) toner.

[Steve21]

From the repeated pattern of failing, I'd say it's most likely gonna be the photoconductor/fuser etc.

 

Might just need a clean, but might need replacing. Check the counter on it.

 

Steve

[will_]

Thanks for the suggestion, Steve. I've checked the page counter and it's only 16,000 whereas the fusers are (I understand) specified for about 100,000 pages (at 5% coverage). How difficult are they usually to clean?

 

The other discovery that may be significant is that the failure seems to be non-linear: if I print a page of pure black, it comes out almost perfectly with just the occasional white spot (in the same repeating pattern). It seems that it's only the mid-tones that are coming out too light.

[will_]

I've got some improvement by swapping the "new" (=remanufactured, shoddily I suspect) toner's drum with the old one. (It's surprisingly easy to do.) It's not perfect but it's certainly a lot better now.