Dell Inspiron 3552 - How To Troubleshoot A Laptop Not Powering On

Hi all, this week's project is a Dell Inspiron 3552 which will not power on. Unfortunately another difficult one this week, and no fix, but hopefully you can learn something from this. If there are any suggestions on better techniques or improvements to my troubleshooting process, feel free to post below.
Hello to our friends in Mexico, thanks for watching my videos.

[@danarepouille1381]

Thank you for mentioning at the end of the video that you tried replacing the CR2032 battery. It looks like an original factory battery, which usually measures less than 3.0V when out of circuit on the great majority of these older Dell laptops in my experience.

[@dzabakwesi2213]

Excellent presentation

[@toannguyen-hf5xk]

Thanks teacher

[@user-bh1tj8df3l]

Hello. I am one of your Mexican subscribers and it goes without saying: I love your content and the comments of your colleagues. Due to the thunderstorms I had no power and heavy rain will continue today. Thank you for your kindness in mentioning the Mexican people. I will give my technical opinion as soon as I can. A fraternal greeting to all.

[@user-bh1tj8df3l]

I left something in your email inbox.

[@celulartj]

@@user-bh1tj8df3l otro Mexican por aca ... aver coleguita em gustaria saber que crees que sea el problema .... en mi opinion hizo falta hacer un reset de la pila del CMOS , tal vez solo este congelado .... falto hacer mas mediciones de resistencia , tal vez alguna fuente se esta protegiendo por que nos pone los valores que le dan pero no sabemos cuando tiempo stuvieron encendidas

[@user-bh1tj8df3l]

@@celulartj Hi. 1.- All voltages are present in the inductors.
2.- U2401, MX25U1001 was the eeprom that programmed
3.- The schematic diagram indicates U2501, W25Q64FWSSIG, another eeprom for CPU, I do not have a board to compare but if it physically exists that one should also be reprogrammed.
4.- If the previous step (reprogram eeprom for the CPU) did NOT solve the problem, then, because the Power LED turns off after a few seconds; We can suspect that a component fails due to temperature (overheating) and not necessarily due to a total short circuit (0 Ohms) as in most SMD ceramic capacitors and here the thermal camera would be of invaluable help. Another way to put it, if the camera detected heat in any component, it would unceremoniously extract it from the circuit.
Finally, if the above didn't solve the problem, then I don't fight anymore. I raise and wave the white flag! because we will have to get another totally similar motherboard for this model (new or used but functional). All the best.
PS1: I wrote in English out of respect for English-speaking colleagues so they can understand.
Postdata 2: Desde luego que hablo la lengua de Cervantes, Lope de Vega y Amado Nervo (mi idioma nativo) y al ver que tu la escribiste se me alegra el corazón. Un saludo fraternal.

[@fouadmida2230]

1- check if there is a shorted mosfet or partial short.
2- use a thermal camera for heat detection maybe you can see something to indicate the problem.
3- try a different bios chip maybe it's a bad one

[@harshabugatti]

If you are confident that GPU and CPU are good, you can use thermal camera. Thermal camera is a very good friend to find shorted micro SMDs (especially the CAPS)
If thermal camera shows heat detection on any IC, check the surrounding CAPS connected that IC.
For a guy who debugs so many PCBs, require a thermal camera (which is used when all the hopes on a PCB is lost)

[@nikolaskallianiotis8622]

I would insist more on BIOS specifically trying more dumps that I could find online or even trying to clean ME region on the original dump which is a possible culprit in situations like this. What about the resistance on the 1.0V rail ?

[@AzuaraRuiz-ot3tt]

(1:12) Check the inductors. (15:16 exactly) PU4502 you should reprogram it again. I am left with the sensation (impression or feeling) that you are one step away from solving it. Good luck. All the best.

[@rasoulvahid7297]

Great Videos and thank you for all efforts. I just have one question and please excuse my ignorance. P Channel Mosfets PU4201 and PU4402. The 19.5v goes through Source of PU4201 and out the Drain and Drain of PU4402 and comes out of Source. I really thought the current travels through the Source and out of the Drain which is not the case here?

[@danarepouille1381]

I heard the beep! As Phil would say, "Shut up, multimeter!"

[@Electricworld-1]

🎉

[@acalat]

You mentioned that measurements for the bios chip Nu. 8 is 1.8 it should be 3.3 . Try to change the bios chip

[@danarepouille1381]

I suspect this is indeed a 1.8V BIOS.