Konica C20 Unusal lines

[dannydub]

I have above,see attached.Black/broken lines in feed direction.First copy out ok after that get lines which slowly get darker.I have swapped black image units which are OM,transfer belt unit changed in Jan this year the device has only done 60k black and 24k colour.Also I have cleaned laser slit glasses.Does it in copy or print and on internal prints.Any ideas,please.

[blackcat4866]

How does it affect the color.? What color are the lines that appear after the voids? Do they match the colors of the previous ~25mm void areas?

What direction are these lines? Crossfeed or Feed direction? Scan or Sub-Scan direction? My guess is Feed direction, and that it's either fusing or secondary transfer, ... or both together. =^..^=

[subaro]

I am going to take a shot at this. Please note, i do not work on these machines.

default the machine to black and white. then print or copy with black only and see what happens.

Next if same with black, print with ledger size paper and stop the print as it exits the fuser. Check the paper and see the impression from fuser backwards. It shold give you clues as to what to eliminate.

aslo see page 414 of the service manual. see below


[uneven pitch ]

Driving unit

During color printing, this symptom
happens with 0.5 mm
pitches.

YES Change the driving unit.


The lines are consistent, so it seems that either a gear tooth is broken or something is not sitting properly that rotates with the diameter of the pitch distance. Are there noise coming from the machine.