I'm a beginner in electronics and not really my field, but I have a dead network switch (Unifi US-24-250W) which, from what I found, tends to have defective PSUs. The PSU on mine seems to be working though, the led on it is on and all the rails (24v and 48v for POE on secondary board, and main board connector) are bringing the right voltage. Everything else, from the status led, to all the port leds, which are supposed to do a pattern when turning on, are dead.
No obvious signs of what could be the culprit, no burn markings or blown caps. The only thing I found is an inductor, near the main processor, that gets hot enough to be uncomfortable to touch rather quickly. Looking on the internet I found about flyback diodes and it seems that a diode is shorted near it. I can't identify the diode but I think is probably something like this: https://www.diodes.com/assets/Datasheets/ds13004.pdf
The markings on it are:
It's just under the middle of the picture, what's on the left is the main processor with its heatsink. I have not desoldered it yet because I don't have a replacement on hand, but in the upper section of the board you can see an identical inductor that doesn't get nearly as hot, and a resistor that doesn't look shorted both ways with the multimeter.
Could this be the cause of the issue? There is a slight coil whine from another part of the board which I wasn't really able to identify but nothing hot nor blown there. Can add pictures if required, the board is the same as in https://youtu.be/0_t1-uP4Q8Y?t=56 but in the video the PSU was at fault
U103, the IC near the probably-dead diode is an AEOSMD with markings:
Here is the datasheet