Beginner question. Did I find a short?? HP dax31mb1aa0 REV A motherboard

[Mess]

Hi beginner here, so I'm not sure of I've done this right 😅 trying to diagnose my laptop's motherboard (dax31mb1aa0 rev a). I don't quite know how to read the schematic, so I'm attaching the pictures of the motherboard and the measurements.

I was attempting to measure resistance to GND on inductors. I disconnected motherboard and used "continuity testing" setting on my multimeter. I put black probe to Ground & red probe on an inductor. Did I measure this right? Am I correct to think that 0.3 ohm measurement indicates a short circuit? Thank you for your help!

[mon2]

Yes, this is considered to be short circuit but the PCB pad that you are testing is very likely the GROUND pad of a bulk capacitor. So this is ok - not a short. Best to study, if available, the boardview file for this logic board to confirm. Also, touch your meter probes together and you should measure 0R3 ohms as well. That is, like our meter in the lab (Fluke), the lowest resistance is @ 0R3 ohms.

[Mess]

Oh I thought I learnt something 😔 unfortunately I don't have the boardview file only schematic. And there's very little writing on the board itself - i.e. not many things are labeled like I've seen on other motherboards that people use to teach on (e.g. on educational YouTube vidoes), so it's difficult no know what's where.

When I touch my meter probes, it reads 0.1ohms. it's a cheap meter though, unlike fluke, so it might not be accurate I guess.:/

[mon2]

Hold that thought. After another glance of the posted pic - can you share a zoomed up picture of this area?

Is the pad that you measured going to pins 1-2-3 (cluster to the right side of this pad you measured) of the missing mosfet? (SOURCE pins)

Pin 4 is the next pin by itself.

[Mess]

Sorry, I'm not sure which pins you're talking about.🤔 Here are the closeups :

and i think this is the schematics of it + the mosfet on its right:

[mon2]

This inductor is switching the power rail for the large BGA device on the left side of your posted pic. Is that the GPU? By design, low voltage rails, like the CPU and GPU will have a low resistance to ground and 0R3 is not considered to be a short. Confirm if the device is the GPU and if yes, which brand / top side markings.

[mcplslg123]

The inductor showing 0.3 Ohms is very likely VCORE or VCCGT coil. However, in both the cases it should'nt read that low. I beleive its 7th/8th gen SOC-so reading should be 2-6 ohms range. Seems SOC is shorted or the dual mosfet is shorted. Worth trying de soldering the dual mosfet coonected with this coil.

[Mess]

Yes, to the left there's a kaby lake platform with Intel® Core™ i7-7500U CPU and Intel® HD Graphics 620 GPU. Should I rather use resistance mode (than continuity testing) to test these? There are some inductors on the other other side of the motherboard that can't test (no beep & infinity measurement).

[mcplslg123]

Your board dont have a dedicated GPU and its iGPU only(part of SOC).
Resistance to GND measurement is always preferred but going by the diode mode readings on the coil which reads 0.3 ,i doubt whether the SOC is alive.
Have you de soldered the dual mosfet?

[DeXXter]

Yes pal, that's a short, also when you're measuring CPU/GPU coils use ohms mode (not coninuity nor diode). Also find the datasheet from that mosfet and measure from drain to source and vice versa (this on diode mode), you can also lift one side of the coil to check on which side of it is the short