Yes, I came back to Thailand yesterday.
The LT control box arrived Texas.
Our engineer hooked it up and it does not exhibit the problem as shown in the movie you sent.
That clip showed that, on power up, the drill chuck slowly descended and never stopped.
To me it looked like the x and z motor leads were swapped because the x axis tries to home on power up, while the z does not.
Are you sure the wires were connected correctly when you test it ?
We do not see the problem in the control.
My recommendation, because the LT is too old, it is not possible to be stable. Problem will come from time to time. My recommendation is to purchase one SD302C, it can run together with your another old LT. The not very good LT can be used as spare for part exchange with another machine.
Let me know what do you think ?