Prusa i3 runs for a while then reverses the extrusion motor

Hi all - I have just finished building a Prusa i3. Ive been working through all the setup issues but I've got to one which I have no idea about.

I have a print running, and it does so for a while, then without warning the extruder motor just reverses.

Video of it happening : Video of the filament backing out of a print for no apparent reason

Has anyone any ideas why this may be the case or what to test for it.

Thanks

Edited 1 time(s). Last edit at 01/14/2017 12:15PM by Krippers.

I would say have a look at the retraction settings in your slicer. Also as an aside the heat sink on the extruder is not mounted correctly. The fins should be horizontal so that this fan doesn't blow down on the hot end.

Thank you I think I have found the issue now. I am seeing file corruption on the start of the gcode. I think its got something to do with the SD card reader, I will try and install a remote print option

Final answer on this issue, it seems that the Hictop prusa i3 has an issue when the sd reader and display is mounted to the frame. I confirmed this by feeding the file via the serial connection and it's been working fine now.