L25500 Horizontal Banding

[SellersSign&Design]

Ah the old L25500, I have a love hate relationship with it. Mostly hate though. So I have replaced just about every part of this printer. I know it’s time for a new one, but I’m trying to squeeze a couple more months out of it. Two days ago I printed a job on 3M 680CR that is only two colors, Pantone 1405 brown and gold. I noticed after contour cutting that there was horizontal banding in the brown. Not horrible banding, but enough of a faint dark/light to be unacceptable in my opinion. Two weeks ago I printed the same job and everything was great. So I’ll run through settings and what I’ve done:

Flexi rip, consistent temps and humidity in the room, all print heads under 1,000 mL with all but two under 500.

I have ran cleanings, automatic and manual printhead alignments, automatic and manual substrate advance alignments, cleaned the advance sensor in the platen and the sensor on the right side of the carriage, checked the maintenance cartridge and the under side of the carriage, and replaced a Y/K and a M/LM printhead. I also printed solid blocks of CMYK, LC, LM and 1405 brown. I have faint but noticeable banding in the Cyan both times I printed the color blocks. Both Cyan heads are under 200 mL of use. At this point, the only thing I know to do is replace the Cyan heads, even though both are practically new. Can anyone think of anything else I’m missing?

 

[SellersSign&Design]

Bump for any help with this... all the inks and printheads are new, I’ve ran multiple cleanings and every test and alignment I know to do, and it’s still acting up and producing the same banding in the brown.

 

[Dan360]

Are you getting the same results on different medias? We have a 360 but I recall having issues with banding on reflective with certain colours. I ended up just upping the passes which fixed the issue or made it not nearly as noticeable, but that may change your colour. Grays and browns were the worst for it because even a slight shift in the colour is easy to see.

 

[SellersSign&Design]

Are you getting the same results on different medias? We have a 360 but I recall having issues with banding on reflective with certain colours. I ended up just upping the passes which fixed the issue or made it not nearly as noticeable, but that may change your colour. Grays and browns were the worst for it because even a slight shift in the colour is easy to see.

I have tried it on both 680CR reflective and 180 non reflective with the same result. The banding is in the brown and cyan, so I think the banding in the brown is a result of a Cyan problem. I’m already running 12 pass. I printed one car with this 1405 brown a couple weeks ago and it was perfect. I don’t know what has happened

 

[MelloImagingTechnologies]

It is time to replace the 25500.
HP is not making long term printers.

 

[Christian @ 2CT Media]

2 things to try as asinine as it sounds. 1 take the ink cart out and shake it. 2 take the heads out, wipe the thermal ribbon with alcohol, shake them, and also wipe the sensor on the carriage for the heads and place the heads back in.

Run a full clean of those heads and try again. I know in the original inks we used to get sedimenting issues if it sat for a week or two.