I updated the firmware on the Hi+CFS Combo in December and since then have had 3 failures of the CFS box when swapping filament. First time I gave up after trying steps 1-3 below. Next 2 times i tried the additional steps 4-6 and was able to resume printing (thankfully as was 60% of the way through a 12 hour print!)
Rewind spool 1 works, CFS fails and reports jam when feeding in spool 2
Manual reattempt shows spool 2 feeding about 20cm into the main tube from CFS to buffer then stops reporting a jam despite no blockage
repeated Extrude/retract of spool 2 fails, print refuses to resume
Unplug the CFS box from printer / wait 10 seconds for printer to report loss / reconnect CFS box
retry Extrude of Spool 2 - this time it fully feeds to print head
Print resumes ok
To me this indicates a firmware problem with either signal loss from sensor or sensor state incorrect as a power reset of the CFS box and re-establishing filament position corrects things, when there is no physical jam issue.
[Edit] Make that 4. Filament jam reported overnight, Cycling through extrude a few times worked perfectly: filament extruded correctly, poop discarded ok, no physical errors, but system kept reporting ‘filament jam’. Unplugged then replugged CFS box, re-extruded and print was able to carry on ok.
Has anyone else encountered this issue with the latest firmware?
I have been battling a CFS issue for the past week. Multiple FR2836 faults on my K2 Plus with the CFS. A jam with no actual jam. The result is I have a new CFS bottom bracket hub coming from Creality under warranty. I have been debugging the issue with that hub and found that the 5-way photoelectric sensor board is at fault and it is a VERY insidious fault. Initially it would randomly show filament was there when it was not. I could blow compressed air between the board and the board housing and it would fix it for minutes. I ran the CFS with the hub hanging out the bottom of the CFS so I could see the indicator LEDs. I removed and replaced two of the photoelectric sensors on the board with OMRON EE-SX1105 ones and found that the fault is NOT with the sensors. The new ones work but the issue is in one of the microscopic board mounted components (transistor or capacitor I suspect). The new sensor now randomly stops detecting filament when it is there and things jam but if I do not use that slot I can use the now three slot CFS with no issues. I do not feel like replacing components that are 1/4 the size of a grain of rice so while waiting for the new hub to arrive I bought a new 5-way photoelectric sensor board board off amazon for $20. Creality knows there is an issue with it and I was able to get a replacement very quickly on the way to me by sending Creality support a video of the problem while on chat with them. In my case it is a component intermittent failure and they are a bear to diagnose because one minute it works and then not and then it works again. I would suggest running your CFS elevated with the cfs bottom bracket hub hanging out the bottom so you can see the blue filament sensing LEDs. Slot 1 was the problem on mine and the led would originally fade on when there was no filament (false on) and then, with the new sensor, fade out when filament was in it (false off). Hopefully this will help remove possible causes or garner some evidence for replacement parts.
It looks like the CFS unit (sensor issue?) is now broken - I get repeated F02838 errors on filament change and not even unplugging/reconnecting the CFS unit to the printer will resolve it. Printing is fine until a requested filament swap then I get failure. Looks like I’ll need to talk to Customer SUpport regards a replacement given it’s under 12 months old.
Check your cutting blade. I had something similar happen on one of my K2 Plus. The filament wasn’t getting cut all the way through. The cutting blade itself was getting stuck and it would leave bits of filament stuck in the extruder or the filament would break off in the buffer, tubing, or the Cfs itself. I resolved the issue by using some ptfe grease in the channel the cutting blade slides back and forth in. Also, check your filament to see if it is hard or brittle.