Vertical Banding

[Carlos4072]

I have many Epson P800 printers, but in one of them, the last days I'm getting a vertical banding in my prints when I print at 720x1440. Usually I print at this resolution because it is better for my workflow. This vertical banding disappears when I print at 1440x1440. Do you have any idea why this could be happening ?? The only adjustment that I did for that printer was the print head height adjustment. I already cleaned and replaced the encoder and aligned the print head.

Edited September 16 by Carlos4072

[anum11]

Your ink assembly may need a flush and maybe some dampers need replacement.

[Carlos4072]

22 hours ago, anum11 said:

Your ink assembly may need a flush and maybe some dampers need replacement.

Interesting, i guess dampers can't be, since i just replaced all the dampers. But... ink assembly... could be, but can you explain to me the logic behind this please ?? Thanks a lot for the advice.

[anum11]

ink builds up in lines, without flushing them clear even if you replace dampers, they will go back to what they were before you replace them. Because dirty ink still coming from catridges and ink lines.

[Carlos4072]

I did the flush, and again replaced the dampers. No improvement. Any other advice ?

[johnson4]

a bad head alignment can do this, did you know exactly what you were doing, or when aligning the marks did you guess? Print an exact size box ( like 4”x4”) then measure it with a caliper, is the image any amount longer than 4” exactly, in the feed direction? 
 

did this machine suffer from a head strike, which you believe it has recovered fully from? 

Edited Thursday at 07:08 AM by johnson4

[anum11]

On 9/28/2023 at 12:54 AM, Carlos4072 said:

I did the flush, and again replaced the dampers. No improvement. Any other advice ?

Printhead itself may be stiffed. In that case ı manually flush printhead and printhead adaptor until it soften. But it is a risky process.