micoair 743 v2, FC does bot power on from battery output

General
1

Issue : Flight Controller Does Not Power On from Battery Input

micoair 743 V2, I assembled it on a test setup using a compatible MicoAir 4-in-1 ESC.When I connect the battery to the system, the flight controller does not power up, and no status LEDs turn on.However, when I connect the FC through USB, the flight controller powers on normally and appears to function correctly.To troubleshoot, I have already verified the following:

ESC-to-flight-controller power cable connection

Battery input and power wiring

Power continuity across the connection path

Connector seating and polarity

All connections appear correct, but the FC still does not receive power from the battery unless USB is connected.

2

So you have the cable connected from the ESC to one of the connectors on the flight controller? Measure the voltage on the other connector (m5-10) on its Vbat pin. If it’s getting battery power you should see it there and show the board is getting power.

3

To isolate the problem apply 12V to the FC alone as follows:

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Recall that internally any FC has the equivalent to diodes to “or” the possible supplies to its internal converters.

In any case, check the battery voltage sensed by the FC when working.

4

I don’t think ORing has anything to do with this case as ORing will be done after the bucks onboard. They are just ORing the 5V or more commonly, the 4.5V pins.