ALTRA8DUD-1L2T LED_FAN2 is blinking red but fan works fine?

Q&A
1

On the motherboard the LED_FAN2 led is blinking red.

The manual says that the LED indicates “FAN2 Fail”

However. It keeps blinking whether I connect the fan or not.

Also; the fan is spinning just fine!

Also; when I disconnect the fan it still keeps blinking.

Also; when I connect the fan to another fan header; that led does not blink.

So I have a feeling the blinking means something else. Anyone any clue? The manual isn’t helping

2

Reboot the BMC, I’ve seen this happen after turning off the system and then turning it back on after a period of time.

3

The fan failure detection seems to be buggy: for a while all the FAN_FAIL LEDs were flashing all the time. I suspect it might be because the logic was designed for server fans while I’m using low noise desktop ones. I just ignored them.