Black streaks when printing from M477fdw

[GMPatt]

When I print I get black streaks down one side of the page. I've tried cleaning pages and they come out as per the attached (they also appear - just more lightly - on the reverse).  I've checked firmware is up to date.  Black toner is half full (OEM).

I understand there is a toner collection receptacle - could this be the problem and if so, where is that and how do I check it?

Any other suggestions?

TIA

[Repairatrooper]

There is no removable or replaceable toner receptacle on this unit. The defect you are seeing is consistent with an issue with the transfer belt and is often caused by a small piece of paper left over from the removal of a paper jam. Open the cartridge door, remove all the cartridges and examine the grey belt that sits at the bottom of the cartridge slot. pay close attention to the ends. If you see some foreign material try to remove it but do not touch the belt with bare fingers as the oils from your fingers will cause additional print defects.

I would also check the cartridge closely because it almost appears that you have a repetitive defect on the page which would suggest a bad cartridge. If the black cartridge has a corresponding line on it that matches this line on the page then you should try another cartridge. keep in mind that HP guarantees image quality until cartridge reaches low so you might be able to get warranty on the cartridge.