Do these ESC's look good to you?

[Prophecies]

Hey,
So I just got all my parts to get FPV set up, and I decided to check my ESC's since I have had one minor crash a few months ago (I have flown many times since, no issues whatsoever).
After inspecting my ESC's, I noticed that they have this white mark on one of the MOSFET's. Every one of the four ESC's has one of the MOSFETS branded with this white mark. It looks like some kind of sharpie or marker. I just wanted to make sure, since it could be a sign of overheating or whatnot.

Also, does the soldering look a little cold? They all seem to have this sludge/clearcoat on them at times. You can see it clearly on one of the photos. It almost looks like water, but I can assure you it's not.

Just want to be sure that my parts are good to go, the last thing I want is to see my beloved bird fall from the sky.

Thanks in advance!

 

[J.James]

That stuff you see on the escs and also should see it on all the factory solder joints is some stuff called "Conformal Coating" Its basically just some clear enamel paint with some UV dye in it to be able to see it with a black light. Its used to help protect from short circuits. and also being that replacement parts dont have it slovered all over them like the stock escs and the main board. I think it also helps dji know if some ones ever replaced any parts. Being they wont glow purple under a black light( you can also see it if you take it out in to the sun being the sun has a lot of UV light and will make it glow purple to.