I am getting an "F-" and the washer just stops. Has anyone heard of this? Thought it was the main elec board but I replaced it for the second time in 1 year and that was not the problem.
What you are seeing is not a regular Duet Sport code, and since you have replaced the main board I am thinking that the likely problem is the Touchpad/LED Assembly, or the MCU or some wiring issue.
Here is a service manual that may help you get it into diagnostic mode, but if the Touchpad/LED Assembly is the problem that is probably not possible.
If you buy the replacement Assembly from this site and follow the rules in the Returns policy you may be able to return it if the replacement does not fix the problem.
Good luck, let us know how it turns out as that may help others (and us too) in future diagnosis.