My Fisher & Paykel GWL15-96155B won't pump the water out just back into tub?

Follow up to my previous post: I looked into this again today. The machine will fill the tub with water, the tub turns slowly as this is happening. When the tub reaches what I guess is the set water level the water pump turns on and the water starts to recirculate from the bottom to the top through the #420400 hose at the top of the tub. The tub turns slowly during this process, after 15 seconds the tub and pump hesitate a fraction of a second then they start the same cycle over and over.

It acts like the board is telling the valve and tub to do this. Could this be a bad board? I've tracked the part number to be 421306USP. At $150 to $175 I'm not willing to throw money at the probelm and see if it's fixed. Is there a more specific diagnostic that I can follow to test the board, components, etc? I need to be sure the board is bad before I spend money on a new one.

Don

Original Post:

My Fisher & Paykel GWL15 washer won't drain, but the pump is working?
I've cleared things from the pump housing a few times over the years. Now I'm stumped. I went through the usual steps to clear out the pump housing, found nothing. Pulled all of the hoses off thinking something was in one of them, found nothing. Pulled the tub out thinking something was blocking the housing inlet, found nothing. I watched the pump run with the tub out and the water just foams up like in a blender, the pump is obviously turning. I looked in the valve thinking it wasn't open but the valve is open. I'm pretty sure the valve's home position is where it needs to be to pump water out. I tried to wash a couple towels and it sits there "pumping" until finally the LED's go out and just the lid locked LED is on, and it kind of gets dim then bright, almost a flicker.

Any suggestions?