Color banding on start of some prints - mainly yellow or magenta

[ml4cs]

Roland SP-540i, Jetbest bulk ink system, printing mainly 3651M, dx4 heads replaced in July 2020, OEM dampers, wipers, captops being used as well

I started having this weird color banding at the start of select prints, which seems to affect Yellow, Magenta, and Dark Blue the most. Green, red, orange, black, brown etc don't seem to show this problem. After it prints a few passes (as you can see in the attached photos) it clears up for the rest of the print job. After drying and cutting and the next qued job starts running it will be fine, then usually after that dry and cut the 3rd job will show the same symptoms. So it skips jobs....weird all same dry times

I replaced the dampers (which created a broken manifold on yellow) replaced the manifold and new dampers on all colors and still have this problem.

I started running a strip of colors across the top of all prints so I could have fewer reprints and issues.

This all started about 2-3 weeks ago, previous 6 months never had this issue.

 

[Jester1167]

Make a block of each color, C M Y K, side by side and try and isolate which color or colors are having the problem. The common theme between all your prints is Magenta. If it is just magenta, replace the damper - ink starvation.

 

[Jim Hancock]

I would suggest making sure the cap lines to the pump are clear. It looks like possible cross contamination, not uncommon on the SP DX4 head printers. If the lines are clogged or draining slowly, when the heads are parked, the ink touches the bottom of the heads. This completes a siphon action scenario on that cap and the ink can be drawn form one channel to the other. The siphon action occurs because the ink cartridges are now "connected" by ink and the 2 cartridges try to equalize their levels.

The other possibility is a fracture between channels. I would suggest as soon as you see the color banding start, to cancel the job and do a nozzle test print - without cleaning first.

 

[Jim Hancock]

In addition, check the "sponge" on the inside of the caps. If this is swollen and raised up enough to touch the print head surface, it can cause a wicking action between the 2 sides of the head. For this reason, I only use Roland OEM caps. Are your captops OEM or 3rd party?

 

[ml4cs]

sorry for the delayed update, I have been working on different troubleshooting things while keeping this printer in production. I went to replace the dampers, again, and the other manifold tip broke off, so I replaced both manifolds now, I ordered "OEM" ones from digiprint supplies but they don't look quite the same, the nipples on top are a little shorter than what was on the head originally. Also replaced the captops with "OEM" from digiprint supplies. Somehow all of this has seemed to make this worse, now the black/blue head is having similar issues and I have horizontal banding on gray and teal now, yellow seems to be better other than it starts our "muddy" and then get to bright yellow. When running test prints the first before a normal clean would show both L channels black and both R channels magenta, run a normal clean and it starts to clean up, running a print the first few passed are not right but then after 5-6 passes the quality is fine.

During All this I am starting to think the pump might be the issue. My reasoning is powerful cleans don't seem to draw any ink into the dampers, I had to draw with a syringe. Today I asked my wife when the last time we emptied or checked or dumped the waste bottle was, she said a few weeks or maybe even more, I pulled the bottle off, barely any ink in there, so could all this be the pump? Would a simple pump replacement fix this? or do I need to replace the tubing, or clean the tubing, I don't think I have extra tubing currently.

Thanks for any help, also while changing the manifolds, I noticed the ribbon cables to the heads so to maybe have some damage to the tips of the cables, where the silver part on the underside is pushed to the side on a few? is that a potential issue or nothing to be worried about?

 

[Pauly]

sorry for the delayed update, I have been working on different troubleshooting things while keeping this printer in production. I went to replace the dampers, again, and the other manifold tip broke off, so I replaced both manifolds now, I ordered "OEM" ones from digiprint supplies but they don't look quite the same, the nipples on top are a little shorter than what was on the head originally. Also replaced the captops with "OEM" from digiprint supplies. Somehow all of this has seemed to make this worse, now the black/blue head is having similar issues and I have horizontal banding on gray and teal now, yellow seems to be better other than it starts our "muddy" and then get to bright yellow. When running test prints the first before a normal clean would show both L channels black and both R channels magenta, run a normal clean and it starts to clean up, running a print the first few passed are not right but then after 5-6 passes the quality is fine.

During All this I am starting to think the pump might be the issue. My reasoning is powerful cleans don't seem to draw any ink into the dampers, I had to draw with a syringe. Today I asked my wife when the last time we emptied or checked or dumped the waste bottle was, she said a few weeks or maybe even more, I pulled the bottle off, barely any ink in there, so could all this be the pump? Would a simple pump replacement fix this? or do I need to replace the tubing, or clean the tubing, I don't think I have extra tubing currently.

Thanks for any help, also while changing the manifolds, I noticed the ribbon cables to the heads so to maybe have some damage to the tips of the cables, where the silver part on the underside is pushed to the side on a few? is that a potential issue or nothing to be worried about?

Id' be replacing that ribbon cable. if you dont make contact, can cause the head not to work properly.

 

[Jim Hancock]

Order replacement manifolds and captops from Solventinkjet.com. I have had bad "OEM" caps from Digiprint-Supplies. I buy a good bit from Digiprint, but get caps and dampers from Solventinkjet.com. They also carry manifolds. All 3 of those items are critical for ink system integrity. Failure of any of them will cause issues. In this case, probably the caps are your problem. And definitely replace the ribbons before you blow a fuse!!!

 

[ml4cs]

Order replacement manifolds and captops from Solventinkjet.com. I have had bad "OEM" caps from Digiprint-Supplies. I buy a good bit from Digiprint, but get caps and dampers from Solventinkjet.com. They also carry manifolds. All 3 of those items are critical for ink system integrity. Failure of any of them will cause issues. In this case, probably the caps are your problem. And definitely replace the ribbons before you blow a fuse!!!

Excellent, I will reach out to solventinkjet.com to order. I was a little skeptical of the OEM captops I replaced as they looked just a little different and the manifolds were noticeably different

How would I know if I have a blown fuse? would things still operate or would they cease to operate?

IF I blow/blew a fuse are they difficult to replace? I ask because I saw a spark on the head (B/C head) last time I removed the ribbon cable is why I am asking, I had it unplugged but didn't do the 3-time press of the power button to de-energize the system. I can't test anything as nothing is getting to the heads right now and I broke my syringe this morning (rubber inside came off the plunger) but should have a new one by this evening.

Learning as I go here, about 6 months of experience so I appreciate all of the advice and tips.
-Thanks
Matt

 

[ml4cs]

Ok I can get ink to pull through, replaced the pump, I believe this was the main issue as now captops drain quickly, after a few powerful cleans there is ink in the waste bottle.

but when I run a test print.....nothing....did I blow a fuse or the board? how can I know?


UPDATE: reading through service manual looks like if no ink is firing F2 fuse could be the issue, opened up the back, fuse is black on both ends so I assume its blown, thankfully it doesn't require soldering! looks like plug and play!

 

[Jim Hancock]

Any update on your issue?

 

[ml4cs]

Yes once fuse was replaced worked with no issues. I believe the root issue was the pump as each other replacement didn’t fix it. It was creating suction and pulling other colors into the ink line. But now everything is new except the print heads.

the team at solventinkjet.com was super helpful with some over the phone diagnosis and helped next day out some fuses to get me running again.

 

[Jim Hancock]

Great people! Glad they helped you get up and running!