Very odd and there's nothing about it in the log. Let's try this, run the machine with only the bad hashboard plugged in. Then let's see the logs.
I pulled out the two good boards and now its telling me "No data yet! Data is currently unavailable".
I will try moving it back to the 1st slot. Maybe it cant boot correctly if there is only a single board in slot3.
I am not qualified to repair this board on my own.