liberty

I am not sure if anybody else has posted on this issue but I have not seen it. When I start up my machine everything runs fine, no troubles there. When I start to print there is a clicking noise and only about 1/2 the amount of plastic comes out. The same happens when I go to advanced maintenance and "move material" BUT when I attempt pushing the plastic through on my own it extrudes normally. I have tried disassembling the rear stepper assembly and the extruder assembly with no luck. I cleaned the thing to a spic and span. (the machine is very well taken care of and I only print with PLA) I tried updating the firmware and every solution I could think of. Even replaced the entire extruder/heating block, and the silicone guide tube. If anyone has any ideas or solutions for what is going on any help would be greatly appreciated. The printer has been down for months now and still have not been able to find a fix.