Roland VP-540 possible bad head?

I would change dampeners first of all (they are a lot cheaper then replacing a head), had the same problem with my sp300v. Careful not to brake the stems the dampeners sits on when you remove them.

I bought mine on https://www.digiprint-supplies.com/. (US website and EU website.)

 

My guess is it is not the head as its firing almost perfect.

 

http://www.solventinkjet.com/
This is also a good site for parts.

 

We have had over spray issues with our Roland SP-540V when our head height is set to high. I know you already you said you have yours set on low, might be worth double checking to make sure it's down. Next I would replace dampers as already suggested. Here's another site that carries Roland parts if you don't already have a Roland dealer connection. https://www.extremeinkjet.com/versacamm_part_s/62.htm

 

You said you've done several small cleanings and a medium but have you manually cleaned around the heads? Maybe you have something attached to the head that is causing deflection. This video gives you a guide for a manual clean. John