It can only be a few things. Plugged manifold. ( the black octagon ) if you remove it make sure to mark it and put it back in its original position.
Dose lines. Pinch valve ( if you remove the line from the pinch valve. Make sure it’s seated correctly again ). Can be a corroded connection. If you remove the connectors. Make sure to put them back exactly where you got them. They are cheap Chinese plugs and can be plugged in backwards. It will short the unit out.
Remove the top case and front tinted cover. Run all the ABC programs. Sit there and watch it run. You can see and hear the pinch valves click. Follow the Flow. Look up on the internet which pinch valves are which. I don’t remember off the top of my head. There’s only one pump for the whole unit. Since A and C are working. The pump is fine. The in and out water lines are fine. When the tester cycles to the B line. Watch and listen. It will tell you what’s happening. You’re not getting water in from the B cycle. Since the test is zero. It’s gonna be one of the 3 things I said at the top.
