Unresolved Jittery arm and not printing all of the layers

Recently at my work we got some Robo 3D R1 to sell and demo. It printed off the box calibration and one thing we downloaded just fine, but then it started messing up. It can be anything from the printing arm being jittery and making the layer globby to it only printing some of the layers. Sometimes it will work and other times it wont. I attached some pictures of failed prints so you can see what i'm talking about. Any idea of how to fix this?

 

top mustache looks like my prints when the z axis fails to continue up. It just stops going up and prints all on the same level... gets all bumpy and ugly. No resolution yet for me.