I share again one finding .
You can use new S5 Hash PCB ( 18 pin connector) with S5 Control PCB (16 pin connectors) Need only a 16 pin cable.
Picture of my water cooling S5 project 3 x old blade + 1x new 18 pin blade.
Click on the image
So it looks like You can use an 18 Pin Hash with a 16 Pin Controller.
Next I took an 18 pin Hash & an 18 Pin Controller & removed the end 2 connections from the connecting cable. This Hashed without problem.
So my betting given the above is that a 16 Pin Hash with an 18 Pin controller will be fine. Just make sure you plug the 16 Pin cable in the correct end of the 18 Pin Controller socket.
Of course the outstanding question is what are the additional 2 pins for?
Rich
I understand that the 16pin end will have 2 pins short in the 18 pin connector on the 3.3v end. Pin 1 being on the opposite end, which is also the square-ish pin. I might receive the stuff this week, i'll report back then.
Hopefully someone figure out what the extra 2 pins is for.