SKR 1.2 died during job

My skr pro 1.2 board died during a job. The tft screen went black. When i detached everything from the board only the 12v diod is lit and it will not flash firmware.

What could have happened? Anyone fixed similare issue?

What was happening during the job?
Your 5V and 3.3V rails are not getting power, so something caused these two internal supply regulators to die. The picture is’t high enough resolution to tell.

The detail that would be most helpful to see is on the right half of your picture above.

Is anything on the display smoked?

You blew two rails. We’ve seen parts blown by moving acis withn power off (not what you report), or bed drops on 3D printers (not what you have)- so not sure,

I’ve fixed a few boards with known causes by replacing regulator parts, I have one that I’m working on now in fact- that one had an attempted regulator replacement that I’m trying to re-do.

if you are good at SMT component replacement and troubleshooting electronics it might be repairable.

One test you could do is to move the source jumper to USB, then disconnect all power from the board. Plug in USB and see if the MCU is alive by trying to connect with a gcode sender.

If so, possibly repairable.

Edit to add: Check your two fuses…

Fuses checked, they are ok.

I was cutting aluminum so probably a chip fried the circuit then.

Probably same price to repair than a new board then here in Sweden. Should a short circuit be visible on the bord if i look?

A scrap of cutting could have dislodged when pulling the board out of the machine, so may not be there any more.

The remaining evidence would be thermal discoloration or visible damage to the regulator parts. Maybe a higher resolution/better lit photo would show that.

Do you use any mist or coolant when cutting? Could that have ended up accumulating on the board?

Sadly, yes.

Edit to add: what does the back of the board look like?

I cant se anything strange on the back of the board. I do not use colant. Only compressed air to blow on the tool.

I have 2 fans cooling the board and they suck in stuff. Have only cut wood i the mpcnc and this was the first time cutting aluminum. Probably should put a screen between the board casing and the work area.

Asked for advice if it was a common fix to this, but now i see it is fried and it was a costly lesson to learn…

Don’t give up yet. First let’s look for simple stuff the photo you show I see a small curl on the Arm chip near C48 close to the Big tree text. Another near C46. Before powering back up ,if you have a ohm meter you can check for shorts buy measuring the resistance from the fuse to grd on each voltage rail.
Maker Jim is most likely right that you have a regulator blow .not bad too repair if your generous with the flux and low temp solder.

I cant see anything, probably need a microscope like the dude at northridge fix.

The only thing i see is some miscoloring at the solder joint at F3, probably not related.

From your original picture:

Ok, now i follow. But if one of those shorted out two pins on the chip, would it not fry the chip itself? Im totaly lost when it comes to this type of electronic work, so i ordered a new board. But will save it if the time comes that i learn more about it. Thanks for the input guys!

Nice job there, how did you add the arrows?

I did this one on MacOS using the preview applet, a quick and dirty way to do it.

If I’d been on one of my Linux boxes, I’d have used GIMP to annotate the image. GIMP sucks for that, but I haven’t found a lightweight alternative. [Queue the other Linux folks to offer a better suggestion]

I don’t know what those pins are specifically.
If they are power INPUTS to the chip, then it’s not usually the chip that fries, it’s the circuit that sources power to the chip. If they are OUTPUTS from the chip, then it might be the chip that dies, or at least that part of the chip.