820-3787 PP3V3_S5 shorted to ground

[bighead]

Hi,

I received this MacBook with a not turning on issue.
They said it wasn't liquid damaged just one day stopped working.
I'm sure it wasn't dropped, because the MacBook looks pristine.

However I'm not sure if it wasn't liquid damaged. There aren't discolored pads on the board.
However around the components I can see some "wet" spots. No corrosion or anything. Just like it was immediately cleaned after a liquid damage.
I'm not sure if it makes any sense.

There is a short on this board. PP3V3_S5 shorted to ground. I can't find the shorted component(s) if there is any.
I sent through 5A this board, but the voltage drop is really big. If it would be a shorted cap or any components I think that component should glow for now.
0.6V at 5A, but I've 0.45V voltage drop through the cables. Which are speaker cables(the thicker one). I've lipo battery here, but I can't control the voltage and I just don't want to set the board on fire.

What should I do?

Thank you.

 

[dukefawks]

Leave the board powered for a while like that. Then use your lips to feel for something hot.

 

[bighead]

I left it on the PSU almost 2 hours and still can't feel anything even with my lips. I'm clueless. I don't know what should I use there.
0.3 Ohm short.

 

[dukefawks]

I have no idea. Crank it up to 10amp, could be a short in the board.

 

[bighead]

I limited to 5A. My old PSU can't do more unfortunately.

 

[dukefawks]

Well, you need to get something else, there is no magic to find a short. Use an old motherboard that still powers on. The GPU or CPU Vcore supply can deliver lots of amps at <2V.

 

[bighead]

Good idea. I'll try that definitely!