Ug. Don't say that - I've disconnected it again now......

I'm pretty sure it's the hash board, but I don't have a multimeter to do what you ask I'm afraid. I've disconnected & reconnected the cables so many times now I'm sure they're worn out..... Seriously though, I've been messing with this for hours - I think we should either try the replacement hash board (with new cables?), or I can box it up for you if you send me a label.

Edit: Just read your post. Right, well if you think it could be a shared component fault - that's either the BBB or the controller board? I didn't try turning the BBB around - just made sure it was properly seated & there were no dry solders anywhere - it & the controller board seemed to visibly check out though. I can go over it all again if you want me to, but it won't be tonight I'm afraid, up early tomorrow & it's getting late. I'm also getting tired of looking at it tbh.......

Have a think & let me know, I gotta eat.....