Blown Inductor - HP Envy 17 - J184NA

[mon2]

Right - shared my local Canadian version of the Mouser links. They are in Texas but ship worldwide. You could probably also source the same from RS Electronics in the UK or pick some up from @SMDFlea's house

[pjzz2000]

Damn, if @SMDFlea's house is anywhere near London, that might have worked out a lot cheaper!

Oh well, it's my first interest and attempt at a motherboard diag and fix and the board is of high sentimental value (believe it or not 🙂), so I'll just have to take the hit as an investment £££££££.

Really appreciate your, and everybody else's help.

Thanks

[pjzz2000]

Latest update: I found soldering the inductor with pads underneath the body and no side contacts difficult and never confident that I had not bridged underneath.

Bought similar spec inductors with side contacts and I think they are soldered ok this time.

No short either side, as before. Not surprisingly, symptoms remain the same. But I've gathered more diagnostics:

Symptom: charger light on, power button light on, doesn't boot to BIOS

Diags:

1. 19.5V rail present all over as input to all other power rails

2.. With charger connected (no battery), 3.3V and 5V present at respective co-located inductors, but after about 20s disappear. Weirdly 3.nV present at various locations, including BIOS and around SIO and power button. Where is that power coming from?

3. When short power button pins, power led lights and says lit

4. Only other sign of action, a 1s flicker of CPU fan

5. After that, no progress. If I short the power button again, the fan kind of high-pitched buzz like it wants to turn but in sufficient power. It has Something like 1.7v on the + connector

6. With power LED on, the 3.3V, and 5V inductors are reinstated and steady

7. Lots of 3.nV and lower present around and directly below the PCH,

8. CPU is cold, like it has done nothing, or next to nothing, which makes sense as no power to them through the various CPU neighbouring Inductors.

So, any thoughts on my theories, or any other ideas?

a) SIO and/or PCH fails to "read" BIOS so don't bother turning on the CPU rail power rail(s), in order to initiate POST.

b) CPU power rails dead for some other reasons (have not felt any heat around that area)

c) CPU dead (or other chips dead)

I have not been tempted yet to try re-flashing the BIOS chip yet because of the way the priblem developed at the beginning: i got the problem sporadically, then it died for a significant time, then it booted to BIOS a few intermittent times. It felt more like a solder joint problem, working sometimes at different temperatures. Not sure how BIOS could have been corrupted and then fine again, then corrupted, then fine.

So Im pretty stuck on what to do next. Im a beginner but learning a lot and determined!!: Any help much appreciated!