Bullet not reading the IBTS Fan Speed

Got the dreaded 6864 error last week. I was able to easily identify that the IBTS fan speed was seemingly an issue (even though there was nothing in the fan to obstruct it). I ordered a new fan, installed it, and still got the same error. That’s when I opened the info panel to look at how fast it was spinning and found that it was not even registering with the Bullet.

Has anyone else dealt with this? I do have a support ticket open with Aillio, but if someone has faced this dragon before and conquered it, I would love any input you may have.

I have made sure the firmware and software are both fully up-to-date.

Hopefully you took pics on the way in and have the images to confirm the connectors. A couple possible installation issues come to mind-

  • 0 rpm may indicate the blades of the IR Fan are contacting the rubber mounting surface locking the fan blades.
  • Alternately there can be an issue getting the connectors seated completely. Check both ends of the cables.
  • And of course you need to confirm you are connected to the correct connectors on the control board.

You can’t be 100% sure you didn’t get a dud but most likely the fan is ok- just a cabling or mounting issue.


Hey @bab!

Thanks for the insight. Fortunately, I did take pictures all along the way to make sure I put things back as they were. I actually bought two fans just to make sure this doesn’t happen again and both of them spin while not being recognized by the Bullet. I’ve checked the wiring to the controller and to the main board underneath and everything is snug and secure. I’m at a loss but have been in contact with Aillio and just got an email this morning from them. I am hoping to schedule a Google Meet with them and get this figured out.

Thanks again for chiming in, I really appreciate it and am glad to be a part of this coffee roasting community!

(Forgive me if this seems like a dumb question) Did you happen to clean all the chaff build-up off the circuit board that sits behind the fan? And blow off (with canned air) any build-up from the pin board and all?

Also, if you don’t mind posting pictures of your connections, that would help in trying to give any ideas to fix it! Nobody likes waiting for virtual meetings…

Not a dumb question at all! I appreciate you chiming in. I gently blew everything off, wiped it with a dry cloth, and used a shop vac (without making contact) to clean the main board. Here are pictures of the main board and controller. If you see anything awry I would LOVE to know!

I had that same problem, and the culprit was the PCB. Take a look here, and note that the pin on the right side is pushed up:

Once I push that down and resoldered, everything was OK.

I’m going to take a very very careful look at that when I get home tonight!

Thank you!

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