Need help identifying components HP EliteBook 840 G3

[Boyan]

Hello Guys,

Can you please help me identify these components from the motherboard. I saw a similar topic, but it was for HP840 G4 (https://www.badcaps.net/forum/troubl...arging-problem) Are those described there the same components?

In the first picture, I have circled in red the burned components. It was due to short switching positive with negative. Probably the motherboard will not work, but I can try to repair it. It is a laptop for experiments, so no big deal if it cannot be repaired.


Thank you

[mon2]

OMG. Good catch on the comparison of the 2 boards! Looks the same to me.

Flux and remove the 3 legged TVS part you have circled. It is intended to clamp the peak voltage to 24v.

[Boyan]

What do you think about the second one which is completely burned? It is the top circle.
Do you think is the same as here? https://www.badcaps.net/forum/troubl...-problem/page2
First post on the page.

In my opinion, HP EliteBook 840 G1, G2 and similar 820, 850 or same generation are pretty much the same. The next one HP EliteBook 840 G3, G4 or G5 can be very close in this part, as well. And all of them can have pretty much the same design in these parts, with slight differences depending on available parts. I doubt HP will bother with designing each motherboard differently, they will try to make as little changes to keep the cost down. Probably many other motherboards are with similar design and components.

[mon2]

Based on the other schematics, the missing part is probably an inductor. Confirm this by removing all power. Meter in lowest resistance mode. Short your meter probes to check the lowest resistance your meter can measure. For example, our Fluke will read as 0R3 ohms when the probes are shorted. Then place a meter probe on one side of the pcb pad that is missing this part. Next meter probe on other nearby parts to locate a part that mates with this missing component. Which part shows as '0R' ohms? We can use this information against the schematics we have to determine which part is actually missing.

Likewise, repeat this process with the other side of this missing part - touch the PCB pad. Then hunt the PCB to locate which other part mates with this side of the missing part. Again to validate which part is missing using the example schematics we do have in our knowledgebase.

[Boyan]

I have attached updated image with the connections for the burned component that I found so far. I think this should be enough for now.

[Bonzas]

I have attached updated image with the connections for the burned component that I found so far. I think this should be enough for now.

[Boyan]

So, any idea what this component is?