Bizhub: Cyan, Magenta don't print nor mix at all below 60% intensity [see scans]

[MonksServant]

I have bizhub c284e. There's been a few overlapping issues with it so it's hard to pinpoint the source of the problem.
The printer no longer prints nuance shades of Cyan and Magenta. It prints them well with 100% intensity, though - that's what's weird.

Can it be the transfer belt's faut?
I've replaced all the drums very recently. I still have the old ones so tried using them once again and it made no change.

Take a look at the scans.
Originals, are the prints that I've done a few weeks ago.
Scans, are the scans of the same files printed now.
cmyk_test.jpgprint_test.jpg
Notice how colors containing only a portion of C or M lack those two tones entirely.
Notice how parts with lots (+80%) of C or M look good.
Also notice the lines at the right hand side.

[elmaligno]

The colored spots, if they match the AIDC sensors of the belt, then you have a bad belt cleaning blade, you can put it from another belt that is better, or buy a generic one or replace the entire belt.

[MonksServant]

The colored spots, if they match the AIDC sensors of the belt, then you have a bad belt cleaning blade, you can put it from another belt that is better, or buy a generic one or replace the entire belt.

Thanks a lot.
As to the intensity of C and M - can the transfer belt be the culprit here too?

[Albonline]

Thanks a lot.
As to the intensity of C and M - can the transfer belt be the culprit here too?

replace the parts run gradation. if not fixed print halftone charts and show us.

[Synthohol]

make sure your optics are spotless.
if you want your copy to look its best > background data initialize and stabilize, toner add cycle, all 9 gradation adjustments and retest.
its never gonna copy exactly the same, you can then bump the density and see if it brings it closer without making the images muddy and too dark.

if you scan at 600dpi the image should be better too.

[MonksServant]

I've found the solution:
It was all the transfer belt's fault. After replacing it all problem disappeared.

Thanks everyone for your help!