Do you Have a really stubborn Nozzle Clog on your Non Stationary Cart Type Printers?
Your printer has this clog that simply will not react to head cleans or the "tried and true" soaking the print head over folder paper toweling wetted with head cleaner or WINDEX with ammonia.

So what to do?
 
The last resort is direct injection of Cleaner into the Print Head Ink Inlet Stems.
The catch is if you are not careful you will do more harm than good.
In fact you could ruin the print head if you are too forceful.
However if you are careful, you will likely end up with a fully cleared print head an another print saved from land fill or recyclers.