Sorry, I misinterpreted what you said about the problem.
If you think there is air in the line to the print head - - - and this seems consistent with your description - - - you might try draining the ink and then “recharging” it.
With the 4880 the process is pretty simple to drain the lines:
Turn the printer on and wait until the screen says “Ready”.
Lift the levers and take out the cartridges (down position locks them in place).
Lower the levers.
Press the Power button to turn off the printer.
. . . at this point the printer will begin to drain the lines.
I think it asks you to raise and lower levers at various points in the process.
When it complete the discharge, it turns itself off.
Turn the printer back on (without the cartridges, but with the levers in the down position).
Raise the levers and Install or re-install the cartridges.
Lower the levers and the printer will charge the lines for the newly installed cartridges.
I have read that the procedure is similar with other Epson printers, although not all models may use levers to lock or release cartridges.
PROVISO: I have only done this with *all* of the cartridges. I do not know what would happen if you tried it with only one or two cartridges, but I suspect it would be a problem. Here’s why:
With the 4880 you change from PK to MK or vice versa by taking out all the full-strength cartridges (side by side on the left side of the printer), and putting dummy cartridges in the C, M, and Y positions before turning off the printer. This drains the
black line only. The lines and cartridges on the right hand side of the printer are unaffected. The dummy cartridges have the appropriate size, shape and chips, but when connected they in effect plug the ink lines so nothing can be pumped out. If regular
cartridges were in place the printer *might* try to pump out the cartridges as well as the lines!
The 4880 drains by pumping out the Black, C,M and Y cartridges as a group, and the LK,LC,LM, and LLK as a group. It appears that the printer will not drain lines unless a cartridge is missing when the printer is turned off, and even then it will only drain
the *group* of lines containing the missing cartridge.
The Epson 3000 might be different in some of these details, but the basic idea should be sound.
Myron
thanks for your detailled feedback. I think I need to clarify my case: it is not about general refilling of cartridges but about charging the ink leading system between the ink-receptor pins, via the ink tubes (the R3000 has ink tubes, like an built-in CIS system) to the print head / nozzles. Usually this system is only charged with ink when you put a new printer to use. The initiation procedure for the R3000 includes an initial ink charge, taking ink from the cartidges and filling up the ink leading system all the way to the nozzles.