New Jarduino build gets started

[ScubaSteve]

Originally Posted by daplatapus

Hmmm, unplugged the PWM fan wire and the fans ramped up to where I think they should be. Anyone hazard a guess what might be wrong? Where I should start looking?

I'd start by poking around with your multimeter. Check the PWM pin to see what the output is and make sure you haven't accidentally reversed the ground and PWM wires, then start checking each part of your fan circuit. If I remember that crazy-assed circuit correctly, there is a chance the transistors aren't saturated and thus aren't acting like switches as they were intended to.

Also, check the programming to see what the minimum and maximum PWM outputs are. Most fans will struggle to operate properly once the PWM drops below a certain duty%.

Finally, make sure your controller and fan circuit are sharing the same ground (not just plugged into the same circuit but literally have their ground planes connected). If they aren't I can almost guarantee that's the problem.