@dc42 I just looked online where to get the TS30041-M000QFNR, but there are delivery delays for at least 2 month for low quantities, but it should be fine to use external 5V and disable the internal 5V, shouldn't it?

I supplied up to 6V to VIN and measured 5V at IO_0 5V_EXT, and it did not stop at 5V but got almost to 6V, I assume that means the regulator is also dead?

I removed the TVS diode and connected via USB. That worked and I could connect to the board.

I will try the bench PSU next.

@dc42 The area around that chip got pretty warm, but not too hot to touch.
also as shown on the pic im my first post, the area around L5 was rather dirty, I cleaned it now with alcohol and a brush.

are there more accessible leads to measure the regulator?

also the pics from the 2 regulators:

@dc42 I used the 2 Pins directly beside Laser/VFD

And I am not getting an 5V or 3.3V (according to the indicator LEDs)

Thank you for helping

EDIT:
I am not very knowledgable about TVS diodes, but I just measured D10 with the big pads left and rigth and it shorted in both directions

Hello everyone

TLDR:

I accidentially used the external Drivers pin to power a 12V fan (which actually worked, so I didn't notice at first)
now I don't have 5V and 3.3V and Windows is telling me, that if I plug it in, that the USB device wants too much power.

Details:

I was replacing my old Duet board, because a Driver failed. So I bought the 3 Mini 5+ Wifi.

Since the layout on the old board changed significantly it took some time to wire everything (corexy with 2 Z motors)

I have a geared extruder with an aliminium body and a fan. While searching for a pin to power the 12V fan, I found one that was labled 12V and GND in the middle of the board.

Everything worked and was fine.

The board was on for several hours and no problems occured, till the next day.

I couldn't get 5V and 3.3V from VIN anymore.

I plugged in USB and it came back, and occasionally stayed after removing USB.

Worried about what happened I unplugged it and tried only drivers VIN and it worked again.

Now I found out that I missplaced the fan plug, and fixed it.

Then I was finetuning the extrusion settings in the web control.

But suddenly after restarting the mainboard it wouldn't power on 5V and 3.3V, and when trying to power it with USB the above mentioned error is displayed on the desktop.

I searched the board for obvious damage, but I am not sure if I found anything.

L5 looks a bit dirty, but I am not sure if it is damage or just dirt.

The entire board (if someone wants to take a look)