How to Fix Power On Issues On Laptop Motherboard (Startup Sequence)

In this video I'm going over the process of fixing my old HP Pavilion laptop motherboard, which was not powering on. I will go over the startup sequence of the motherboard, as well as, checking for power supply voltages at different stages of the power on cycle.
Equipment used in this video: Multimeter, and Microscope
Software Used in this video: Board Schematic, BoardView, Px2325 (microscope software)

[@siyabongahlongwana2386]

Thank you so much sir, this is the first time in You Tube I have found a great teacher in Component level repairs on motherboards with easy to understand language

[@xxycom8963]

Thanks for an informative video 👍. You achieved your goal of nailing the problem in attacking it in a rough “outline” style going directly to measuring the 3.3 and 5 volt rails. What is desired is a full power sequence analysis starting from the adapter voltage, to the charging IC, and Power Source selection between VBATT and ACIN. The information you present is a latter stage of the power sequence. I wish you will also present the earlier stages where at a component level the starting sequence is presented, and the logic explained of the decision to select the adapter or the battery. Such an explanation will provide the basis for why the 3.3 and 5 volts will not be present, or why the battery is not being charged. I am hoping you will find the time for preparing such a video. Your use of board-view in conjunction with the schematic and then measurements, made your way of presentation outstanding compared to other videos on KZbin.

[@rossmoodley9407]

Search Dr Bios - how to read laptop schematics part 1 - youtube channel.

[@jositojosito9124]

Tank u sir for this masterpiece. Informative important video

[@Swenser]

Why did you suspect the bios? How does it fit into the sequence? What are the logical steps?

[@mikes78]

Thankyou for this, This has helped me identify a problem with the 3.3 & 5v reference voltage IC on a laptop.

[@danielmuregi9088]

great man be blessed for your good information

[@ScjRepairShop-]

great job sir. you have made a very informative video about the boot sequence . i have learned alot of it . thank you very much more power to you sir . Godbless

[@sinumanimani4378]

Nice explained thanks for your information

[@Arturochirinoscruz]

Excelente video gracias ingeniero, saludos desde PERÚ 🇵🇪 sudamerica.

[@abassjubril]

Good day, please how I my going to use the boardview together with the schematic

[@jerry_f1298]

Very good videos, all the stuff on the repair laptops videos are great, can you make more videos like this or make more videos teaching us how to read or the sequence to read the schematics to try to solve the problems on bad motherboards, and when we can decide that the Logicboard is no reparable , I have a Toshiba u945 that starts, fan spin, power leds turns on, but the is no video at all, I replace de bios, the 2 chips, and still there is no video, I replace too the board battery as it was not charging at all, I hope you can guide me on how to resolve this issue or to know if this motherboard has no hope of being repaired. thanks :)

[@rossmoodley9407]

Brilliant

[@prasaadkrishna]

Do battery powerup require charging ic?

[@tyranttype1984]

Hola, quería preguntarles si es posible encontrar un diagrama de un notebook. Sufrió un cortocircuito y se quemó un componente muy chico, el drama es que justo se quemó el numerito que tenía y me es imposible encontrar repuesto. El modelo es este: DA0G3EMBCD0 REV:D

[@dariovicenzo8139]

Who provide the 3 volt before ldo is enabled?

[@kenatcotaxis9532]

super

[@danielshearer5016]

ty

[@johngape12-5]

helpfull

[@sanelb1147]

I am not sure if my comment got posted before. On my Lenovo t410, I am getting 3v on reference point pin, but not the 5v. Also I am not certain what the kbc chip is on my Lenovo the u42 or u23. Both of those chips are not getting any power

[@sanelb1147]

I already replaced the 2 MOSFETs after f2 fuse as they were not passing any voltage,

[@malik9001]

Thanks for the video, actually it's my first one am watching on your channel. So I'm asking: can you tell me about where to get such schematics, because it's so good. Shows the number of chip pins and everything well .

[@Roottech25]

google search.... they are freely available to anyone. can't remember the website

[@malik9001]

@@Roottech25 I try most of the times to look for schematics, but, to get one like that you had it ain't easy, so the website is crucial, but it's fine if you don't remember it. I still much appreciated the video

[@truenorth388]

What kind of microscope camera? make / brand name?

[@Roottech25]

amzn.to/3yEvyjz

[@siyabongahlongwana2386]

What types of tools do you use and how do you get spares?

[@user-rn3eb2jn5t]

For laptop repair you need a multimeter, dc bench power supply, hot air rework station, soldering iron, microscope, thermal camera, tweezers, picks, screwdrivers. You can buy dead laptops to practice with, test yourself and work on. All the best to you!👍🏻

[@abdulxvvl4218]

How to buy schematics of proline

[@Roottech25]

search online... google is your "friend" ;0)