I'm sorry to hear of your frustration, and am here to help. Thanks for supplying detailed information, to help reduce the number of questions I need to ask, and get you back to happily printing ASAP.
After reviewing your order history, I see you bought a set of R3000 carts and ConeColor ink bottles last December.
So, the VM cart ran empty about a month ago, but was working well again after refilling the cart and doing an ink charge cycle, up till recently?
Was the VM printing consistently well, then suddenly stopped printing at all, or did some nozzles drop out and the channel gradually stop printing?
Are all other channels printing well?
Did the VM channel drop out while printing, or did you notice the channel wasn't working when printing a nozzle check after the printer had sat unused?
Do you always shake ink bottles before filling/refilling carts?
What are the temperature and humidity levels in your printing environment?
Please examine your VM cart- is the exit chamber at least 1/2 filled with ink?
Please open the printer cover, and examine the internal ink lines- are they all filled with ink, or do you see air inside?
How many of what size sheets did you print of the QTR-VM flush image thru QTR calibration mode?
Have you cleaned the bottom of the print head, following our instructions?
Have you done any cleaning cycles? If so, what type of cleaning cycle, and how many did you do?
Have any parts ever been replaced in this printer, such as the dampers, wiper blade, capping station, and/or print head?
Please let me know so I can help resolve your issue and get you back to happily printing.
Best regards~ Dana