Hi, it's the same info we replied in the other thread where you asked:
https://forum.luminous-landscape.com/index.php?topic=144894.msg1266423#msg1266423In short, weigh the head to check for air. The MK side is probably empty (and maybe also clogged on top of that). And there's possibly some air in the MK line in the printer. Buy a kit to purge the air and reprime the head. Then check all the other heads and lines and do the same as needed.
Your R is being contaminated by MK because of the air issue. If you don't fix the MK side the R won't work correctly either. And if you don't fix the MK side the thermal head will burn out anyhow.
Even if you don't print with MK, the printer still uses MK during maintenance cycle, etc. It's designed to have all 12 channels working correctly whether you need them or not. Leaving one "blank" leads to other problems...
Or just find a replacement head, but it's better to preserve the ones we have as long as we can since they are discontinued.