Hi there, I also own a Heiz 1200 machine and i got the following problem.
From time to time the stepmotors start to run by itself, just a little , a few steps at a time.
At first i thought its an error from the pc ,as it looks like an interference signal caused by a bad grounding of the system.
So i started to take the controlunit apart, and found out as soon as i removed the backpanel (wich holds the D 25 pole connection) the problem was solved.
So in my case it seems to be some kind of a groundloop. Anyway i disconnected the D 25 pole connector, sealed it with some heatshrinktube and since then the machine runs perfect |