I thought I had posted this update on this forum, but perhaps I did not.
IF you have air in an ink line one solution is to do an Initial Ink Fill/Charge. (Why would this happen since I don’t let my carts get close to empty? Answer: I was using the large Inkjet Mall carts on my newer p600 and accidentally lodged the plug into the air vent underneath the cap of LLK.)
You can’t do this yourself with the P600, but you often can with the 2Manuals Adjustment Program ($20.00) which you can download here; You will be buying the Service Adjustment Program, not the Service Manual.
However, if the program is saying that your chips are indicating low ink, or ink out, (Despite the fact that the carts are full of ink.) you can download ANOTHER program so that you don’t even need chips. Once your printer is “chipless” the 2 Manuals Adjustment Program should work.
There is a chipless firmware solution at the 2manuals site but it indicated that it would not work on my version of p600. You can see if yours works by following the instructions here. Activation Key for making Epson XP-760, EP-807A Chipless Printer (for one device only) - Service Manuals download service (2manuals.com)
Walker suggested the following Website:
InkChip.net which has a way to make a printer “chipless” using this program: Chipless solution Epson, activation key for Epson - Ink chip
You can run this InkChip firmware program. It will make your printer not need the chips. You will need to download and run the programs per instructions, which are very clear (with 1 exception were it wants you to hold something for 3-5 seconds and I thought I was waiting for a screen so I held it too long and got the wrong screen, which was a problem.) You have to buy an activation key for $45. Windows and a USB connection are required.
After you have completed the chipless firmware and activation program you can go back and run the Adjustment Program selecting Initial Ink Charge to remove the air from your ink line. Make sure your carts are quite full so you don’t run them dry.
If you get messages saying your ink is out, then open up the ink cover and close it again and the message should go away. It did for me. Maybe I will have to do this all the time; I don’t know.
I think I have cleared the LLK line of air! Many days of trouble shooting and patience perhaps has paid off. Let me know if I can help anyone else. Also, don’t forget that from now on you, and only you, will be monitoring your ink levels.