Epson R280 With Stubborn Clog

Hello. I’ve left my Epson R280 (a dye based printer) idle for too long. It now has very stubborn clogs. I tried direct flushing with Piezo Flush. No change. I tried flushing with distilled water. Again no change. I left the fluids in over night. Only black and magenta are missing some parts of the nozzel check lines. Any advice is greatly appreciated.

Joe Kohler