Epson printers dont like mixing epson and non epson cartridges in the same printer at the same time. You should replace all epson cartridges with compatibles and not one at a time. Though most of the time the printer will recognize the cartridges even if mixed, the different ink formulas can cause streaking and the black can look grayish or greenish.
Run the replace procedure from the computer - not the printer. If your printer has a display screen, it will tell you which cartridge needs replacement or which cartridge has an issue. If it doesn't have a screen, the red light can be flashing on the printer and you have no way of knowing what is the problem. If you run the replace procedure from the computer, it will display the cartridges with an X through the one it doesn't like. You can then try to reseat that cartridge or replace it.
If the printer doesnt recognize the cartridges immediately, turn the printer off for a minute. If that still doesnt work, remove the cartridges, turn the printer off and on with no cartridges. Reinsert the cartridges and turn the printer off and on again. If that still doesnt work, email sales@ccs-digital.com
Don't worry too much about the ink level shown on the printer. Epson printer ink levels are notoriously unreliable and even worse with non epson cartridges. Remember that the chips on these cartridges can get reset to full even if you don't refill the cartridge. The backs of the ink tanks are transparent and you can see how much ink is in them. If a newly replaced cartridge shows half-full, just wait until it shows empty and go through the replace procedure to reset it to full.
Don't wait until the ink is empty to refill. Since the chips get reset to full, it's possible to print with an empty cartridge which can damage the printer. Keep an eye on the black, since this usually goes fastest. When the black is down to about a quarter or when the printer warns that it's low, take it out and check it. Whenever you replace an ink tank, check all the others and replace them if there is less than a quarter of a tank left.
Note that there must be some air space above the ink level or the pressure can cause it to leak or spew ink, so ink tanks are not filled all the way to the top. A cartridge has enough space for 30 ml of ink but is only filled to 20 ml.
Video showing replacement of reusable Epson ink cartridges:
Read the other articles on www.ccs-digital.com about ink jet care and solving cartridge problems.