820-02098-a A2442 No Power / Boot

[2informaticos]

First of all, welcome to the forum!

That corrosion should be the reason of the short.
RP850 is practically connected to PPBUS_AON.
Clean that area and rebuil the traces, if necessary.
Then check if the short still persists.

Many boardviews have strange representation for several transistors and ICs.
That shouldn't be a problem to locate the signals by their names, not by components.

A2442 - 820-02098 - M1 Pro.rar

drive.google.com

Use this one, if you prefer...

 

[2informaticos]

6 ohm to ground at PPBUS_AON is practically short.
Check if any coil gives you the same reading.

BTW, I can't find FS200/1 in schematic; do you mean F5200/1 instead?
Once removed, the short remains on pad 2?

 

[economypilot]

Hello! I did mean F5200/1 sorry about that. The 6ohm short remains on pad 2 with the fuses removed.

I checked all of the coils and they all have readings in ohms that are much higher. The lowest reading was still several hundred ohms. I identified the coils visually -- all the gray squares. I couldn't figure out a way to search boardview for part type... but I got all the ones I can see of the various sizes.

So that's where I'm at. Did you see the picture I took of the PCB I damaged at CN479? Just wondering if I exposed the ground plane or something and that although I reduced the conductivity with my cleanup efforts there's still inappropriate conductivity happening there.

Thanks for your help!!

 

[economypilot]

okay. I went to town on the hole with a micro carbide bit in the dremel. First it dropped back down to a dead short, which was sad. But under the theory that you can't break it if it's already broke I kept going and now have a reading of 26 ohms. It'll be a neat trick getting one capacitor to bridge over to the other pad and solder them together but I think I can manage that. But is 26 ohms in the range of what we'd expect to be appropriate?