Aside from almost cutting my pinky off, I bought some stepper extensions that I did not check closely. Normally I would not consider stepper extensions to be a problem, since how can somebody screw up 4 wires and 2 connectors (he, he), but mine were mis-connected. The result was steppers that did the boggie but not much else. I also had a problem with the display not working (lit but would not show anything). I just had the wrong display defined in the Marlin configuration.h:
should have had this:
Got that fixed and it works great. What is most important to me though, is that I got all axis working, endstops are endstopping and themistors are thermisting - and the heaters work too, so all the important systems are go.
Since I did not want to have this mess of wires are electronics flapping in the breeze I was able to salvage several failed prints to make a sort-a enclosure for it all. The fans are all tired into PSU now since previously I was too lazy to take apart the PSU to connect them in. Once I get this calibrated, printing an enclosure will be at the top of the agenda, well after several other projects that have been piling up.
This is running Marlin 2.0 and I am just using the original drivers (A4988) which I've connected to TL-Smoothers. Now that I know it works I am going to order some TMC2130 drivers since they should work with the Re-ARM (which is pin limited compared to the Arduion Mega).