Acer Predator GH51M LA-K862P NO POWER Cant Find shurt

[Sephir0th]

I am not referring to any schematics or boardview since it is not necessary for such a repair attempt in most of the cases. I am referring to your Black probe which has touched the pad where the Mosfets are located and not the side where the Main power rail is located. This was NOT the requested measurement. The power rail will be separated if the Current Sense resistors are removed and for this reason it is very important on which side you measure.

We need to understand why you got a low reading anyway, which is not expected.

Were both resistors removed or present?

This need to be clarified before we can move on. And a perfect example why it is basically a bad idea to remove these resistors. Now I had to write tons of text and It confuses the whole approach, or, if your measurement is right, it confirms a issue on the charging controller side, which would be a big surprise at this point.

[isa198585]

Look, let's take PRB3 and PRB46; there is no short to GND on pins 1 and 2. There are only a few components on this side, and they work without any problems, which is why they were removed. However, nothing changed after I put PRB3 and PRB46 back on; the measurements are still the same. I'm sorry that you have to write so much because of me. I am so sorry about that

[Sephir0th]

Try again to find a secondary ower rail which shows almost continuity (less than ~3 Ohms) with the Main power.

If you can't find one, you are allowed to raise the current/voltage in steps up to normal operating voltage while injecting into the Main Power rail.

But be aware that neither me nor someone else does take any responsibility if you missed the secondary power rail and therefore kill something caused by overvoltage sending into one of these secondary power rails.

Personally i'd prefer to have resistance to GND measurements of any single power rail present on this board before.

[isa198585]

After a longer inspection of this board, I found that PQW1 and PLB1 are very hot, reaching 105°C

[Sephir0th]

...How much voltage was injected ? Still 16 Ohms on the Main power rail? Resistance to GND of PLW1 ?

[isa198585]

I connected 3V. On PLV3, it has reduced to 0.3 ohms; previously, it was 1.6 ohms. But on VCORE PLZ1, it is still 1.6 ohms, and when I connect 3V there, the CPU gets hot

[Sephir0th]

I am explicitly asking for resistance to GND of PLW1, so +FBVDDQ.

+VCC_CORE has nothing to do with the shorted VRAM and even PLV3 rather indirect at most.

+VCC_CORE, respectively the CPU might be fried now, caused by exceeding the maximum of 1 Volts while injecting... or maybe not. However, this would mean it was missed a second High-Side failure. We will see what we can do at this point after you share the requested measurement, but per 99,9% a donor board now.

[isa198585]

PLW1 is still 1,6 ohms

[Sephir0th]

We can't do anything for the board anymore.

[isa198585]

I think also. thank you so mouch for your Help.