C364 Black fading on one side

[oversizedbass]

Hey all, I recently inherited an older C364 unit for free. It's in surprisingly good shape for the amount of use it has and the relatively little maintenance it appears has been done throughout its life. I am trying to track down the source of a black printing problem however and would love the input of someone more knowledgeable than I.

Here is a gallery of what the gradient and halftone test pages look like - the color ones are performing as well as I would expect, but on black prints there seems to be one side that is quite a bit lighter. It started appearing in regular prints so I ran off these color tests and I think this has narrowed it down to just affecting black.

Copy-4.jpg Copy-3.jpg Copy-2.jpg Copy-1.jpg Copy-8.jpg Copy-7.jpg Copy-6.jpg Copy-5.jpg

I looked into the condition of the consumables and it looks like the developing and drum unit for black are very very sad and old

pic2.jpg pic1.jpg

Would it make the most sense to start with a black developing unit for this issue?

Thanks for any help you can provide!

[SAR]

Clean the print heads first, then replace the black drum. You should also replace the M & Y drums, they are way past life.
Before you replace the black dev unit, you can try running the corner of a piece of paper between the mag roller and frame to clean any chunks away. This will get rid of light straks in dev units.

[rrrohan]

pretty sure if you swap the colour and K drum chips around you can try then put the colour drum in the black spot. if problem follows the physical drum then that would be a free way to confirm if its drum or dev

[tsbservice]

K dev is damn cheap no way to save over life developer unit spilling dev all around.
I would put new black drum too.

[copyman]

Did you try cleaning the print head with wand clipped on inside front door? If that don't work put a new black drum and / or developer unit. Don't worry about the color drums, replace as needed. You "inherited an older C364 unit for free" so putting a few hundred dollars into it you are still way ahead of the game. By the way that copier, the "4" series is one of the better copiers kon/min ever made. Just my humble opinion after 40+ yrs in the biz.

[Ziggy]

Depending how dirty the print head is the wand may not get it clean. Its not that hard to pull the print head assembly to do a good cleaning of the print head

[copyman]

Since it's just black causing issue no need to pull print head. Just clean with wand and most likely have to replace at least the drum. If you take DV unit out you can see laser glass to clean more thoroughly.

[copier tech]

Toner builds up on the charge grid over time. You can easily strip & clean this, or simply replace the black drum.

The black developer is not the issue.

[oversizedbass]

Thanks for the helpful suggestions everyone! I started with the easiest - swapped chips and drums, and when I do so the issue follows the drum, so I'll start here and then get into it further if replacing this doesn't do the trick!