You need to take a systematic approach to solving this issue. Also, the protect the pump message just means the pump motor needs to cool off.
I would suggest you try pulling ink through the magenta and yellow dampers to see if the clog is before or after that point. The following items will be very helpful to do this:
https://www.amazon.com/Glass-Syring...luer+lock+glass+syringe&qid=1600521514&sr=8-8
https://www.amazon.com/gp/product/B01LM8LTTO/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1
Pick the needle that fits tightly in the bottom of the damper (a bit of cleaning solution on the needle will help the needle go in easier). Remove the ink cartridge for that color and pull ink until you have air. This will tell you that line is clear. I would insert a cleaning cartridge at this time and pull some cleaning fluid through and then remove the cleaning cartridge and pull air.
I would put a new damper and O-ring on the ink line at this point. When replacing the damper O-ring on the ink line, snip off 1/16 inch off the ink line so the new O-ring is at an uncompressed section of the ink line to insure a better seal. You can get dampers with an O-ring here.
https://www.solventinkjet.com/product-page/roland-small-damper-o-ring
After installing the new damper, insert the ink cartridge and fill the ink line. When doing this, position the syringe so the damper is upside down so you can get most of the air out of the damper. Before placing the damper on the print head, clean the manifold post with a swab and cleaning fluid to remove any dried ink residue.
As you have replaced the caps, all that is left is to check the print head. Remove the cap line for the M/Y head at the pump, attach the syringe and very gently try to pull ink through the head. Depending upon the results, you can decide if you need a new printhead.
