The IBTS fan was ‘working’ in that it was rotating. RPM was down to as low as 4,xxx rpm before the roast started. When things heated up the speed would increase to 10,000+ rpm, even up to 14,000-15,000 rpm. ErC 6864 had just been added to the f/w and it dropped power to zero because my fan speed was too low.
I had thought that IBTS fan speed was controlled and that what I was seeing was ‘normal’. That’s not the case. IBTS fan speed should be relatively constant at over 10,000 rpm though the f/w-generated ErC allows a speed as low as 5,000 rpm (before the roast starts).
If you think you’re having a problem, contact the Help Desk for Aillio and include your s/n. They can look at the codes thrown by your Bullet (they’re saved on the Aillio server) and tell you if you have a problem with the IBTS fan. Then, if you bought from Sweet Maria’s, they’ll send you there to get a replacement fan.
Switching fans is relatively easy. I have a post here about that.