L1800 - ecosolvent - new printhead???

[Stuart21]

I have an Epson L1800, fitted to a Chinese flatbed; printing ecosolvent ink from Korea (South), onto plastic items. I just fitted a new printhead - sourced from 3rd party in China - but looks like an original

I have cleaned the printhead a number of times, also powerflushed, but not getting any better than below. Actually, this also looks like the problem I had with the previous printhead!

Anyone know what could cause this? Grateful for any guidance!

Thanks, Stuart.

 

[Ink stained Fingers]

I would assume that this problem is ink-related, e.g. the solvent drying pretty quickly. I have not used such inks
but I would try the 'normal' cleaning methods but with a clear eco-solvent, a cleaning agent compatible with such inks,
and doing first the soaking of the printhead from underneath with a piece of kitchen paper soaked with such agent and shifting the printhead onto it for a while. It that does not change anything then going the next step removing the dampers from the printhead carriage and using a syringe with a short piece of tube to connect to the ink receptacles and slowly pulling and pushing the solvent out and in several times.

 

[The Hat]

Could you have gotten a dodgy refurbished print head and not a new at all...
This can also explain the bad nozzle check...

 

[turbguy]

Air...wait 24 hours, try again and post..

 

[Stuart21]

Thanks for all your suggestions - but nothing is improving it. It is not air as I bleed the head with cleaner before putting it together.

I am thinking it must be electrical as nothing I do will give a good pattern. Used up two printheads and 1 mainboard last 48 hours -

Have checked FFCs - no breaks, no shorts -

Had this prob on an off for months. ;-(

& can't get Epson service (even paying) cos item is modified -

 

[Ink stained Fingers]

I still think it's ink related - not the correct consistency for this type of printhead, but this only could be tested if you are able to transition the printhead to run with regular dye inks for a short while. You could use refill cartridges which fit into the printhead carriage instead of the dampers Epson is using in the L800 so you won't need to change inks in the tanks and tubes.

 

[turbguy]

If the pattern changes from nozzle check to nozzle check, it's air.

 

[Stuart21]

Well I have found the problem. Not printheads, not mainboards - it is in the tube leading from the cavity below the printhead when the printhead parks (there are 2 tubes - one goes to the pump, the other goes to a valve of some kind. Looks like this valve was not closing (or tube split) - so pumps vacuum was not getting to the printhead. Pinched off this pipe, cleaning worked well, after 2 - 3 times, and a soak of the face of the head with thinner, all jets now firing!

Over3 months! & as I said, Epson don't want to help. Shame, because as an inventor, I have some things I would like to discuss with them ;-(

Thanks you guys,
Stuart.

 

[Ink stained Fingers]

Thanks for the feedback, that's one of those errors which are quite impossible to diagnose remotely, you have been persistent enough to find it.

 

[berttheghost]

There is a lesson here. Always clean and check the purge unit (routinely or in the case of a clog). If a purge doesn't remove the cleaning fluid from the purge pads, don't expect it to be pulling ink from a printhead.