CFS and K2 Problem . Buffer not working?

Flagship K Series
,
1

The first 3 week the printer whit cfs was working well. i had to print a big project whit the same filament so i started to use the lateral spool instead of the cfs.
Now i can print only from the spool and not the cfs. When i try to extrude from cfs the filament is loaded correctly , but when start to extrude is look as the motor of the CFS and the extruder is not synced . when i look the upper part of the extruder i sow the tube is moving like the cfs is pushing but can’t go, after i got and error.
Usualy the first error is Software-triggered sustained overcurrent followed by an error jammed.
After the error whitout doing anything if i make retract the filament everything is fine or if i extrude from the lateral spool everything work perfect.

I think is the buffer that is not working. (opened checked cleaned and look fine mechanical).
The blue light is always on, (i don’t remember if when trigger the stop have to turn off or change color i can’t check if working )

I already changed :
The filament sensor above the extruder,
All the ptfe tube. (verified the filament goes smooth)
The Noozle

Thanks

2

I’m having the same problem. 3 CFSs started giving problems on the same day.
I’ve already done everything they told me to do. My last attempt will be to install the 3 x 4 mm PTFE. I think the problem is in the firmware.

3

Having the same problem with my K1C and CFS-upgrade. Filament is loaded correctly. The print starts good, the buffer is working a few times, but suddenly the buffer runs empty and the CFS is not triggered to feed more filament. Problem is, there is no error code.