Alienware m15 R1

[MOCCOR]

Hi. I was gaming one night and my laptop suddenly shut off. It wasn't a long session, maybe 20 minutes at most after about 24hrs of no gaming inbetween, so it shouldn't have been super hot. The PKCH2BB for sure must have "popped" as it slightly cracked the clear plastic underneath the "A" button. The SM4365A looks a little yellowish from what I seen and also had the black plastic sheet melted to it before I scrapped it off. I ordered replacement components for both of them and I kinda want to give it a try replacing them. But does anyone have any idea if it is worth it or should I check elsewhere for a problem first?

I am comfortable with soldering, but when it comes to knowledge of components to test for problems, my knowledge is only beginner level. Weirdly, the DC power connector looks untouched, which is right above the 2 components. And the AC Adapter never "shuts off" if I plug it into the laptop, but I am not sure if that is a good or bad thing. I recycled the laptop battery long ago due to pillowing, so that kinda sucks because I feel like that would confirm whether it was just simply the Charger port or something like the CPU/GPU.

I tested the AC adapter with a meter and it is fine, I tested the AC-DC adapter and it is fine, so its something between that DC-IN connector and the laptop, which surely is one/both chips, but is there anything else I should test? Thanks for any help

[Sephir0th]

You can test the mosfets by setting the multimeter in Ohms mode and measuring between Source (Pin 1,2,3) and Drain (Pin 5,6,7,8), between Source and Gate (Pin 4) and between Drain and Gate. There shouldn't be a reading below KiloOhms. Orientation of the Probes doesn't matter. And add a resistance measurement of the Second Mosfet Drain compared to GND

[MOCCOR]

Thank you for the response. I measured the two in what I hope was the correct way, and these are the results -
SM4365A, https://datasheetspdf.com/pdf-file/1...r/SM4365NAKP/1
Source to Gate = 114
Drain to Gate = 0
Drain to GND = 0

PKCH2BB, https://datasheet.lcsc.com/lcsc/1912...BB_C384597.pdf
Source to Gate = 115
Drain to Gate = 115
Drain to GND = 0.240

I should also mention, I did give the board a couple look overs and I didn't see anything obviously bad, other than those two mosfets having burning discoloration so I ordered them ahead.

[MOCCOR]

I don't see any edit button anywhere, but I do have another question. Normally my laptop would max around 88-90C, which is decently below the "safe" temps. It's possible other components were hotter than others, but do you know why this component might have burned up? The schematic shows a operator temp of up to 150C, so I find it hard to believe it hit 150C, but not impossible. 2 things might have contributed to it.

1. Laptop plugged in 24/7 for a couple months, maybe that component only goes "idle" when the charger unplugs?

2. I designed a 3D printed vertical laptop stand (with lid closed). In my test, it showed slightly less temps for the CPU and GPU. But I didn't take into account that other areas could have gotten hotter. So it is possible the verticality + lid closed = hotter PKCH2BB. It was just kinda weird that I had 3-4hr gaming sessions no problem, and then suddenly during a 15-20min session it burned up

[Sephir0th]

If the parts were already degraded then it is more question of time than a question of load. It's just coincidence that it happened without heavy load present. Maybe it will result in a economical repair, maybe not.

Because if the SM4365A reads 0 Ohms to GND (Please confirm!) then you have more problems than just the shorted Mosfets:

A short-circuited Main Power Rail in addition, which needs to be troubleshooted separately.

Does any inductor present on the mainboard read the same 0 Ohms to GND?

[MOCCOR]

I redid the test and still got 0s until I used black (COM) on Drain and Red (VmA) on Gate + GND. Pretty sure I used the same colors on the PKCH2BB but idk if that makes any sense. Or maybe I just simply didn't press hard/accurately enough, my mistake.

So the new values for SM4365A are -
Drain to Gate = 739
Drain to GND = 465

Not sure if those values are good/bad since my knowledge of mosfets is pretty basic, I greatly appreciate your input. And ty for the information of degradation, that makes sense for a 3-4yr old laptop

[MOCCOR]

If the parts were already degraded then it is more question of time than a question of load. It's just coincidence that it happened without heavy load present. Maybe it will result in a economical repair, maybe not.

Because if the SM4365A reads 0 Ohms to GND (Please confirm!) then you have more problems than just the shorted Mosfets:

A short-circuited Main Power Rail in addition, which needs to be troubleshooted separately.

Does any inductor present on the mainboard read the same 0 Ohms to GND?

I tested all of the inductors I could easily see and they all seemed fine, none of them read "0" but some did read 2s, 3s, 7s. But from my research they are usually low numbers. Some of them were 60s, 70s, 160s depending if they were on the outside or near the CPU/GPU. But no 0s