I just had this problem with my SV04 which has 2 extruders. I had sovol customer service helping but I eventually after much frustration found the issue on my own.
I was sent a new motherboard because my bed heating in the motherboard registered 0 degrees. I installed the new motherboard exactly to that of the old one. Making sure every single plug was carefully pulled, then then plugged into the new motherboard one by one. The motherboard is unrelated other than my issue started AFTER I replaced the motherboard.
Started with the firmware to be flashed. Everything look good and I started to print. First print I noticed the black gear stuttering…moving about 1mm in both directions very fast then it wasn’t stuttering, it was printing/extruding perfectly. At the exact same spot for layer 2 and 3 and so on, the stuttering would start then stop, and continue printing.
Starting a new print it would do it in a totally different place on the bed, 2, 3, even 4 times in 1 print.
I could push the wheel manually, and it would move, but that was it. The filament would extrude if I manually turned the wheel.
As time went by, as in a couple of weeks, it got so bad, that it stopped extruding filament altogether and would just do that stuttering movement BUT, it made all the gcode moves.
Customer service told me to swap the Extruder wires in the motherboard board. That did not resolve the issue. It made the left one move but the 2nd extruder stayed put and the black wheel/gear moved on extruder 2 without moving on x or y.
Finally, I took everything apart pertaining to both extruders, which by the way Sovol thinking it was a defective extruder, sent me a new extruder, and that one had the same issue.
The fix: I swapped the stepper motor cables completely. Taking the cable from behind the gantry, on the pcb where the ribbon cables reside and from the other end on the steppermotor.
Issue fixed for extruder 1 but now as expected, extruder 2 has the issue. Which tells me I have a faulty stepper motor cable wire. I will be getting a new cable wires from Sovol since I’m still under warranty or I might just order one from Amazon.
I hope this helps. I scoured the internet looking for help. None was found. So I hope this helps you and anyone experiencing this frustrating issue.
