MKS Gen 1.4

Hello, I am having an issue that may be a failing controller but I wanted to see if there are other possibilities.

So what its doing.... its just stopping randomly during a print for no reason I can see, the usb drops from the print server and the head stops right where it is, but the bed and hot end stay on and at the set temp.

This can happen early in the print or late, I had it fail at layer 3 of a 13hr print yesterday and last night it failed at layer 785 of a 939 on the same print..... lots of waste there

I do get prints that work, about half of them...

So I have tried two different PSU and I turned up one a little to 13.5v thinking maybe the voltage was browning out and the cpu was locking up when the voltage dropped a little.
It seemed to get worse there... not better..
I started thinking, I have TMC2100 stepsticks on this, I wonder what happens if they fail, overheat or what have you. I have it fan cooled, well I might add.... The drivers are not running crazy high, like 1.3v at the test point and I am pretty sure they can run up to 1.5v easy.

not sure what to look at, I am pretty confident in all my settings and I am not getting an error at the display panel.... it just stops printing.... The head just stops where it is, the panel continues to show the temp and everything just stays hot and waiting.

Marlin 1.1.5 btw

its like the gcode stopped coming in.... maybe my USB cable? I am thinking of things as I type I will try a new USB cable when I get home.... and test an unplug to see if that produces the same fail...

Edited 1 time(s). Last edit at 11/06/2017 02:09PM by JustSumGuy.

pulling the USB cord from the AstroPI print server produced the exact failure.

I have changed USB cord, but the possibility of a bad usb on either the Rpi3 or the MKS Gen 1.4 is still there.

I am starting a 20hr print as a test now.

lets see what happens....