Unable to arm due to PWM failure

[mazi14]

I had been using Matek F411 Wing mini FC in my plane for years. A year ago I moved this FC to another plane (wing) and flashed the newest iNav FW (7.1.2). I made first flight succesfully, but then I get message like "Unable to arm due to PWM failure", when I want to arm. What does it mean? What can I check or how to get it work again?

[sensei-hacker]

Normally that means you're trying to use a servo that doesn't exist. Like you assigned pitch to to the sixth servo, but you only have four servos.

Can we see a screenshot of your mixer, please?

[mazi14]

I have already flown with the plane and this set up, but next attempt I got the message. Servos are connected to S3 and S4, ESC to S1 port of the FC.

[sensei-hacker]

Servos are connected to S3 and S4, ESC to S1 port of the FC

That's two servos. Your servo mixer says the third servo is controlled by throttle. There is no third servo.

[mazi14]

Thank you very much for your advice. It helped.