Epson SC-P600 Inconsistent Nozzle Checks, Missing Channels, Why, and the Repair

[RiverRat01]

Sometimes the initial cause is really simple when these initial issues start appearing. Is there a buildup of pigment ink on the left side of the carriage? If the P600 or 3000 exceeds three years of use. This buildup will end up manifesting itself in strange situations in inconsistent nozzle checks for no reason. All Epson printers need to be checked for buildup of solids on the left side,
The buildup causes the nozzles to be blocked when the printhead rides over the crest and gets this muck back on the underside and blocks the nozzles. For some reason this buildup is hardly addressed by Epson. Seems like built in obsolescence for the uninformed owners.
At the same time the wipers may needs to be cleaned at the same time. Buildup of sticky dirt will not allow a clean wipe on an auto windshield. So dirty wipers simply redeposit pigment solids back into the nozzles.
If there is buildup all this disassembly etc. might have been down the garden path of destruction due to disassembly and improper reassembly.

My preparation has, thus far, paid off. I determined the least invasive way to remove the bottom base. The new capping station is installed. No loose ends; no broken or extra parts. All fasteners accounted for. Although, I have to say, not for the faint of heart. Apropos of your comment regarding the left side of the carriage area. The waste pads serving this area are totally saturated and solidified. Ink has been running over the sides of the waste pad frame and collecting in the bottom panel. Ink has been dripping very close to the pressurizing motor. I am still debating rather I want to replace the rolling air pump (pressure pump). I took photographs but have not transferred them to my desktop for uploading to this forum. I suspect that I will not flip the switch and run an ink charge until Sunday or Monday. If people in the forum express interest I can outline how to remove the bottom panel. About the only trick is the WiFi frame.

 

[RiverRat01]

I quickly realize that cleaning the waste padding is futile. Not even denatured alcohol dissolves the solidified ink on the schedule that I am up against. I may plan on a second tear down to replace the padding under the left carriage area. I have looked for padding for the P600/R300 over the years, but have had no success in finding it. I can't find raw material at this time. I happen to grow microgreens on jute. Thus, I have a large amount of jute. I may replace the saturated region with jute for now. Or, I may simply reassemble with the new parts and verify whether the printer is repaired and go from there. Possible I could cut padding to fit from another printer model padding that is readily available. Any suggestions for a long or short term solution to replacing waste padding in the P600 are appreciation.

 

[nertog]

I quickly realize that cleaning the waste padding is futile. Not even denatured alcohol dissolves the solidified ink on the schedule that I am up against. I may plan on a second tear down to replace the padding under the left carriage area. I have looked for padding for the P600/R300 over the years, but have had no success in finding it. I can't find raw material at this time. I happen to grow microgreens on jute. Thus, I have a large amount of jute. I may replace the saturated region with jute for now. Or, I may simply reassemble with the new parts and verify whether the printer is repaired and go from there. Possible I could cut padding to fit from another printer model padding that is readily available. Any suggestions for a long or short term solution to replacing waste padding in the P600 are appreciation.

Do you mean the square sponge pad on the left of the carriage? It's not connected to the rest of the spongy area and can be removed. Just pull out the left and right tab with flat tweezers (or push them through from the other side...you have removed the printer's bottom anyway). A nice soak in warm water will dissolve the dried sludge.

Interesting to read about the pressurization system and valves in the ink delivery path of the P600. I have a couple of R3000s here, but never had to go that far to fix them.

You have no air gaps in your ink lines, right? Have your tried pulling ink through the tubes + dampers by inserting a syringe in the ink outlet of the dampers? Ink should flow easily and without creating air bubbles in the ink supply lines. Maybe there is an air pocket somewhere and a good pull with a syringe helps....?

How's the capping station pump performing? When you add a bit of cleaning fluid or water to the pads, does it flow away quickly and equally on both sides?

Keep us updated!

 

[RiverRat01]

Thanks for the information regarding the sponge on the left. I did not realize that it was separate. I just tried to remove it using plastic trim tools. The sponge is so gummed up that I can't remove it as a single piece. It tears in layers. Thus, I quit trying to remove it for fear of removing it in pieces. I could spend much time on cleaning up and replacing waste pads. I am doing major repair work. If I fail to repair the P600, I don't want to have spent hours upon hours of time making custom ink pads. I posted earlier that I had jute; but I just realized that I also have bamboo grow medium for micro-greens. The bamboo grow medium is almost identical to the waste pad material. I have not been able to find replacement pads, OEM or otherwise, for the R3000/P600.
There is a 3" by 16" horizontal waste pad assembly mounted to the bottom panel that runs below the carriage area. The padding to the far left is beneath the sponge you refer to. The waste padding to the far left is saturated with semi-solidified ink. So much so that ink has been running over the edge of the padding frame and accumulating on the bottom panel. I could simply cut the saturated padding off with scissors (or maybe a hacksaw) and replace it with bamboo grow medium but I think that I will wait until, one way or the other, I know if the parts replacement restores the P600 to proper operation. If so, then I will do a second tear down and focus on the waste padding.
Yes. vacuum applied to the damper outlets draw ink into a syringe. All eight dampers behave similarly in this regard. Nonetheless, the ink delivery system that I recently installed had been ink charged before I bought it from a company that was doing P600 DTG conversions. The ink delivery assembly sat on my shelf for three years in shrink wrap. Possibly, despite being "new," it is bad, but I don't think so. Just in case, I have a new OEM uncharged ink delivery assembly ready to go as a last resort. I am hoping that I don't need to install the new delivery system. If my efforts succeed, I am betting on the capping station as the key replacement leading to proper operation. I installed the new capping station last night. I am starting reassembly today. If all goes well, I will have her assembled and ready for an ink charge tonight or tomorrow. Fingers crossed. Thank you for the information.

 

[RiverRat01]

Keep us updated!

I have learned much in the last day. Your prediction that the damper filters were clogged is apt to be the most correct. As you know, I was working on replacing the capping station. This was not easy. You have about 1/32" to work with to drop the old and replace with the new. This took hours of fiddling. There was no trick except for removing a seemingly unrelated machine bolt that was protruding in the path of the capping station on the way in and out. There is also a grease cover over a roller bar that needs to removed to open up a path. Then the mist box needs to be removed to clear the path. Of course, the bottom plate has to be removed.
The new capping station is installed. Reassembly went well, no left over parts; everything accounted for. Upon powering the P600 there were no errors. I ran a few head cleaning cleaning and there were perfect nozzle checks for the achromatic channels. The color channels were nearly dead. My waste counters were in the 90% plus status. I bought a reset key, reset the counters, and ran an ink charge. To my dismay, the ink charge did not restore the color channels. Thus, the capping station does not appear to have been a main problem. Nonetheless, I am glad that I replaced it. I think Epson recommends replacing it every few years. Mine old capping station was original.
Out of frustration, I gently cleaned the print head for a second time. VLM and LC came to life for perfect nozzle pattern but then went South after a head cleaning cycle.
I am relatively confident that I now know what happened. The P600 had been working perfectly on a near daily basis for 4 years. I let the PK line suck air. Ultimately I performed an ink charge and everything but the achromatic channels went dead. Ironically, PK came back with perfect nozzle checks. I reported earlier that the dampers all allowed about 0.25 ml of fluid to be drawn into a syringe. They behaved the same for channels that were working and channels that were not working. Today, after the manual head cleaning showed promise, those promises were dashed by a head cleaning cycle. I shifted my attention back to the ink delivery assembly.
Yellow and Vivid Magenta have not showed signs of life since I installed the "new" ink delivery system. The "new" ink delivery assembly was charged by the seller. I don't why the seller would have even bothered to charge the system, they were doing DTG conversions on what I believed to be new P600s. I bought the assembly for 40 bucks and it sat on the shelf for four years. Once again, I shifted my attention to the dampers. I removed the Y/LC damper and immediately saw the likely problem for Y. Big chunks of solidified yellow pigment were in the chamber.
You mentioned that the dampers are one-way, but you can manually gate the valve by holding the membrane in while flowing fluid. I filled the chamber with Piezoflush and let it set for an hour. I was able to clean out the chamber and restore flow. The same for LC.
I have a brand new OEM delivery assembly that I have not installed. I am stubbornly trying to make the currently installed assembly work because I would like to keep the new assembly for a spare. And also because I don't want to mess around, again, with cable routing etc. I hit a snag, however, that will require me to further experiment on an old damper assembly. The VM damper is totally blocked. The VM damper as you may know, is tied in with the PK/MK damper and switch. It seems that I may need to dissemble the damper assembly to get at the VM damper. I have the original damper assembly to play with. But, for now, I am out of time. My day job and sleep beckon. I suspect that, before this is over, I will be installing the new ink delivery system (includes the damper assembly). Chinese vendors are selling isolated damper assemblies for the R3000/P600. I noticed that the Epson service manual advises to never remove the the ink tube ribbon connectors due to inevitable leakage. Nonetheless, there are YouTube videos showing disconnecting and reconnecting the ribbon tubing. Maybe Epson overstated.
What do I think happened? I think that the ink charge applied to a 9 year old ink delivery system dislodged pigment fragments in the lines that, in turn, clogged the dampers; except for the achromatic colors. There must be something about the achromatic pigments that makes them less likely to from a sediment. I should mention, my P600 has only seen one set of Epson cartridges and that was in 2016. The saga continues.

 

[nertog]

Very interesting read! Regarding clogged Y + VM dampers: both those inks have significantly higher pigment load (= solids) than the other channels.

 

[RiverRat01]

Very interesting read! Regarding clogged Y + VM dampers: both those inks have significantly higher pigment load (= solids) than the other channels.

I completely tore down a P600 damper assembly from the original ink delivery system. I wanted to know if the two dampers mounted nearest the PK/MK switch were same part as the other three dampers. They are. Removing these two dampers unlike the other three, requires disassembly of the damper assembly. The distribution plate needs to be removed before removing the dampers. The motor shaft controlling the PK/Mk switch needs to be rotated to position the arms in a neutral position so the the motor assembly can be removed without damaging the switch.
I flushed, by vacuum, about 200ml of hot water through each damper chamber. I drew about 100ml from the outlet and about 100 ml from the inlet. Pigment sediment in the chambers broke apart and always left the damper while drawing from the outlet; never from the inlet. I find this a bit alarming because it seems that the pigment sediment forms downstream from the filter. Thus, if there is a build-up of sediment in a damper chamber and a small piece breaks away, then it will go straight into the head.
I suspect that when I did not original ink charge, two very bad things happened. first disturbed sediment within the dampers broke apart and lodged in places causing the dampers to clog. And pieces of sediment that escaped the outlet went directly into the head with now intervening filter.
I have three damper assemblies. One is brand new OEM that I am hoping to leave on the shelf. I ordered a dozen new dampers from a Chinese vendor with the intention of rebuilding two damper assemblies. They dampers not arrive for two weeks. Thus, I attempted to clean the original dampers and the PK/MK switch.
I installed the newly flushed assembly and, to my delight, all 8 channels were live. Perfect nozzle check on the achromatic channels plus VM. Even the PK/MK switch worked. But then I did a super clean and lost the color channels again. I suspect that the head is severely clogged by debris dislodged from the dampers. Further, I have Piezoflush in the cartridges. It might be that the Piezoflush is breaking up sediment downstream from the damper filters. Currently I have 6" columns of Piezoflush on each of the eight head ports that I am letting in place for tonight.
What a lessen to learn. Had I replaced the dampers as consumables every couple of years I might not be in this mess.

 

[RiverRat01]

Update: I can't believe how much I think I may have learned. The PA600 still has 3 channels - Y/LC/C that are essentially dead. Perfect nozzle checks in the others. Nonetheless, I still have hope that I can fix it. It was a mistake to install a new damper assembly on the old head stage. Upstream debris immediately clogged the Y channel of the new damper. The dampers are next to impossible to clean with non-aggressive technique. I have successfully cleaned them, as defined by low resistance and visual inspection of the filter, with Greased Lightening, This is really strong stuff and I don't feel good about using for fear that it may damage an otherwise uselessly clogged damper.
I am back to the basics at this time - delivery from the cartridge to the print head. I tested my cartridges for flow resistance while installed in the cartridge bay and drawing through the ink tubing, but not dampers. While making comparisons to a fresh cartridge flow rate with distilled water and used cartridges primed with distilled water, the flow rates are all over the place. I have five sets of cartridges for the P600. Not surprisingly, the yellow cartridges have the most resistance to flow. A couple were nearly blocked. I cleaned them with greased lightening but I can not get the flow rate to match a fresh cartridge.
Thus, I have ordered a new set of new cartridges and ink and will start from ground zero. Through all of this, I removed the print head and it was clogged. I was able to successfully "waterfall" the channels after back flushing with hot distilled water. My hope is that the head will turn out to be usable. I am still betting that I can return the P600 to operation.
Meanwhile, I am buying an Eco Tank Epson for my "routine" work.

 

[RiverRat01]

Update. I have had a boxed ET-8550 sitting in the corner for a few weeks now. I am avoiding opening the box because I have not given up on the SCP-600. I know that if I put the 8550 into operation; I may give up on the P-600. Ultimately, I much prefer to have a working P-600 over the 8550. And, I, hesitantly, prefer the 8550 over a P700/P900. I want the pigment inks and the third party option. Plus, I have supplies for the P-600.
I am back to work on the P-600 today. I previously reported that I bought a set of 38XX/R3000 dampers that did not fit the P600. The seals were too tight and the head nozzles bottomed out on an inside wall of the damper. I have since been studying these dampers making comparisons to my original P600 dampers. I think I simply got unlucky, again. The dampers I received have thicker internal walls, tighter seals, and square (rather than round) filters. My bet is that they are 3D printed and may not work in any printer. The the vendor's credit, they accurately photograph the damper. Thus, you can see the differences between this particular 38XX damper and other 38XX dampers being offered for sale by studying the vendor's photographs.
Meanwhile, figuring I have nothing to use, I put the head through some aggressive cleaning. The P600 head appears to be more robust that the other heads I have destroyed. In all, I have probably put more than 200ml of various solutions through each set of nozzles. They all waterfall. For this, and other reasons, I still have hope that the head is good. I am still of the belief that the problem is upstream from the head.
Until I recently switched a damper position, The P600 showed perfect nozzle tests for LLK, LK, and PK. Thus, I have been able to use it as a viable B/W printer for my current needs. And, thus, I have not needed to take the 8550 out of the box. After a damper swap, I lost LK altogether. I hesitate to do another ink charge until I have the head and ink delivery system as good as I can make them. Soon though, I need to print color.
My belief as to what happened remains the same, I let air into the PK line. I executed an ink charge and the P600 nearly died. Then to make matters worse, In installed a "new" damper assembly. This assembly had been previously charged and setting on the shelf for three years. I have since learned that sediment will collect in the damper chambers distal to the filter. Thus, disturb the sediment with an ink charge and it has a straight shot to the print head nozzles. This is what I think happened. My print head was fine until after an ink charge pushed sediment downstream from the dampers.

 

[RiverRat01]

Update and background summary. It seems that my SCP-600 suddenly developed ink delivery problems at several locations in the ink delivery system. The printer went from printing perfectly (so I thought) to being unusable following an ink charge aimed at one channel (PK) that appears to have loosened ink sediment in all channels. So far, clogged cartridges (refillable) and clogged dampers have been identified and replaced/refurbished. In the case of severely clogged cartridges and dampers; severe cleaning with various solutions failed to remove the clog. I recently ordered concentrated ammonia, a component of "Pharmacist's" recipe. As a kid, remember pure ammonia being available at local stores. In the modern world, I had to order it on-line. I have "commercial" Windex on hand that will not loosen the clogged cartridges and dampers. Neither will denatured alcohol. Some of my fiddling with this is more academic than repair. Ink "cement" is not easy to dissolve.
Despite many setbacks, the SCP-600 is doing much better. Five of eight channels are now giving perfect nozzle checks. Two of five channels have two non-roving nozzle "clogs." One channel (Cyan) has about 50% of the nozzles firing in roving positions (air or sucking air). I have yet to do an ink charge, but I have done a few "super cleanings." Generally, when improvements from head cleaning become asymptotic, I quit and shift my focus. When, or if, I manage to coach the Cyan channel to 90% or more nozzles firing, I will perform an ink charge.
Possibly, through my efforts, I have "discovered" an out-board head cleaning technique that is more effective than "routine" flushing and water-falling. Because of desperation paired with frustration, I have removed the head on five occasions for cleaning by flushing. I have been around the block with this before. Flushing a head with a pressurized syringe is dangerous as heck. You can easily blow membranes and destroy the head.
When flushing the head, I always collect the solution and inspect for ink particles. I noticed that, despite, successful water-falling, rarely were there ink particles in the flush. On the contrary, ink particles collected in the bath of fresh cleaning solution that I used for back flushing.
At first, I thought that the ink "cement" in the clean bath water must not have been coming from the nozzles, but instead from the head framing. But after five cleanings of the framing during each of five head removals, there were still new ink particles showing up in the clean bath solution. Ink particles appearing in the clean bath continued despite water falls for all eight channels. I was puzzled.
The bath contained is a flat porcelin soap dish having sides about 1/8" high. Thus, even if the dish is entirely filled with solution, the height of the solution is well below the electronics and connectors (sealed with packing tape when working with the out-board head). I noticed that, sometimes, when lifting the head from the bath, I could feel the head sticking to the flat porcelain due to breaking surface tension. Then it struck me. Perhaps the ink cement in the clean bach was, indeed, from the nozzels and that the suction of breaking surface tension was more effective than water falling. Thus, I played with small amounts of cleaning solution on a glass surface aimed specifically at maximizing surface tension. To be continued. (Yellow went from entirely dead to 100% nozzle check after playing around with surface tension suck).