The plot thickens....
The additional discussion got me thinking, especially reminding myself that the illumination of the tx LED on the ttl adapter still worked.. so I figured let me try the Eggrider and my phone.. @mxer it seems that the issue may be my controller or the cabling to it as the Eggrider too will not communicate as far as programming is concerned. Still works as a display as does my 860C without issue.
So I think my initial thought that the ttl adapter crapp'd on me is incorrect. Now I'm thinking it's either the wiring harness... Though wouldn't that give me a display problem?... or the controllers internal communication hardware. My cables are in the frame and have only been unplugged once or twice between initial install and now.
hmmm... What to try/test next.
I hate parts changing but with these tiny higo connectors and no spare cables to cut up as testing leads it may be the easiest.
Can you not try a continuity test (sound) on each end of the harness with a multi meter shouldn't have to remove from the frame if you can get to either end of the harness
!Son of a BITCH! So I went down to troubleshoot a little further... and no @mxer I can't access the bottom end of the 1T4 main harness cable easily because the motor end is heatshrunk and inside the frame...
So I tried my usb adapter again and indeed the Tx LED flashes on command... Same happens when I try it with the phone/otg. So I tried the eggrider again and it to wouldn't communicate to program either.
So I plug everything back together and go to try the throttle and nothing... now the motor isn't running. This is actually a good thing because now the display is also showing the dreaded 30H error, loss of communication. So now I know that the problem has to be where I'm fiddling around so I play with the cable near the connector and the display shuts off. Long story short I hack off the higo, cut it open and solder 5 new wires to the pins. Quick splice it back together and everything is working. Tried the USB adapter/otg and that is a go as well.
What had me sidetracked at the beginning is that while the programming wasn't available the display and controller worked perfectly and without error codes for the past two days. Plus I had played with the connector as I did now and no change at that time..
So the take is... Fock with s*it long enough till you totally break it so it's easier to find the problem.
I ordered a 20" display extension cable which should be long enough to replace the male end with a nice neat splice and have enough on the female end to make a new programming cable when the CH340 arrives.
A quick update...
I decided to replace the 1T4 main harness instead of soldering up the display cable as I thought it a better job in the end. It wasn't my initial thought as I knew removing it from the frame would require removing the motor power wire and having to redo its splice that's tucked away in the frame as a well.
I also thought that now having a spare 1T4 cable would allow me to slice it open and use it as an access point to all conductors for future troubleshooting.
Anywho I took my time and about 2 hours later all is ready to roll.