I found an error code on fusion TEST A FAIL. I ran a manual test A only. Same TEST A FAIL. Went to the unit and found a lot of reagent in and under the unit. Don’t know what to do now?
This is due to the waste line being blocked I think. As the trident tried to purge itself of a test the pressure builds up as it can’t escape. This exact thing happened to me and it turned out my wage line had a tiny pinch in it. Contact Neptune and they will swap it out for you. Only issue I then had was the replacement unit that was sent out to me was a bit rough. Scratches all over it and a part of the outer casing was broken where it clips to the base. I’m very carful with my gear and this really disappointed me. It means every time I pull the drawer out I struggle to get it to go fully back in.
IME, it is usually caused by one of the lines shown in your picture coming loose. Hard to get to but there are videos on line that show you how to get to and fix them.
I had an issue also of the same type and had good service on troubleshooting thru Neptune, hose partly coming off due to waste line blockage causing back pressure.