[Misc] C6501 fine lines in transport direction

[mr.propper]

Hello,
C6501 sometimes makes fine lines (0,1mm) in transport direction.
It is always pure color, 1 of 4 colors, and in different positions. They go about whole page completely.
Often this helps clean to the developer unity, but not always. Sometimes she disappears by itself.
Do you have ideas?

[Cantechman]

I have seen streaking and lines on a 5501 when it was due for a 100K pm. Maybe your corona units are bad?

[mr.propper]

I have exchanged corona and drums together.
The line remains in the same colour and position.
I can exclude this.
mr.propper

[Stirton.M]

If you are attempting to do a halftone of any one of the 4 colours and get a white line through, check for fuzz under the dev unit, or dirt on the slit glass that is blocking the laser path, and clean as necessary.

If you are getting a coloured line where none should be in white space, check for fuzz on or near the drum unit at the charge unit or just before the developer brush. Clean as necessary.

Check the cleaning blades on the drum units. Check the cleaning blade on the belt unit. Check for dirt and debris on the 2nd transfer neutralize assembly.

[HORSE]

100% it's a hair or fibre hanging down in the laser path under the Dev unit, check with a flash light for fibres under the drum surface potential sensor. Like Stirton.m says check the 53 test pattern@ 100 or 62 test pattern and nail down which colour the issue is in. I use a lint free cloth wrapped around a thin screwdriver shaft to clean under here.

This is a very common fault in these machines

A dirty corona grid will give you dark lines in the half tones, a lined drum will give coloured lines in the White areas.

[Cantechman]

Yeah right I forgot that. I ran into that problem before and it was a small fibre from the cloth that was in the laser path.

[mr.propper]

thank you for yours answer,
but I have thin coloured linie on white papier.
if I the drum exchange then I exchange cleaningblade with.
a dirty Laserpath isn't possible, that make white strips.

[sbillis]

thank you for yours answer,
but I have thin coloured linie on white papier.
if I the drum exchange then I exchange cleaningblade with.
a dirty Laserpath isn't possible, that make white strips.

what color your lines are?
in some place are straight and some place are dashed? they are randomly on your paper.

I have blue lines (if we are talking for same think) and appeard whenever they want. If the machine will stay off for couple of hours then maybe will print ok. Some cases next day.

I 'm still trying to fix this out because is not happening every day. First things that I have do are:

• reverse cable from machine to controller,
• change the cable,
• clean the controller and Video interface on machine
• clean the Image and Memory Board

After that I am thinking to replace the controller and maybe Image or Memory Control Board.

I hope to help you

[Stirton.M]

thank you for yours answer,
but I have thin coloured linie on white papier.
if I the drum exchange then I exchange cleaningblade with.
a dirty Laserpath isn't possible, that make white strips.

As I mentioned before, I was illustrating what dust can do in two separate instances. Fuzz blocking the laser will make white lines.

Fuzz touching the drum will discharge the surface, similar to a laser discharging (writing) the surface, and toner will be attracted to the drum. Sometimes the fuzz can be on the charge assembly, or someplace between the charge assembly and the developer brush.

Basically what I am saying here is you can eliminate that possibility by ensuring there is no fuzzies, which can come from anywhere. I use a can of compressed air whenever I do a PM to rid the area of any dust particles and fuzz. The charge assemblies are never cleaned, aside from using the wire cleaner or compressed air to remove dust from the assembly in between PMs. I leave the grid alone as this can easily be contaminated with fuzz from a cleaning cloth. I prefer to simply change them out at the required PM time, so this never becomes an issue.

Other areas of possibility would be a contaminant in the developer. Bit hard to eliminate this, aside from restarting the affected colour, or exchanging the unit itself.

You can try troubleshooting by swapping units around. For example, you have a magenta line, swap one at a time the charge wire, then drum and then dev unit with the cyan colour. When swapping the developer units, place some tape over the toner add holes to keep from contaminating the colour in the dev unit with the other colour you are swapping with. This should only be temporary, it is just to eliminate the unit as a cause of where your problem is coming from.

If the problem persists in spite of changing to another colour, as the example above, you changed the drum, charge and dev unit with cyan, but the line still shows in the "magenta" halftone tests, then in all likelyhood you might have a writing issue, as sbillis mentioned. PRCB, laser unit....it could become involved. Best to eliminate the toner side of things first.