About the motherboards .... (part 2)

[@JonathanAnon]

I think that this may be the channel that I've been waiting for all these years!!

[@thingshappen9199]

@和諧 except i need 100/100 vision to see that fucking cursor

[@johnmellor6065]

cant thank you enough Sorin , i hope your kindness and generosity comes back to you in bucket loads

[@NarasimhaB]

Yeah me too hope the same for sorin. This is just overwhelming load of precious and useful knowledge.

[@joziphstu]

This channel really is an electronics repair school Many thanks, great work

[@ChrisChris-io4qv]

I appreciate your efforts and am very grateful for the tutorials. May you be rewarded for everything Sir Sorin!

[@alimoradkhan1]

That was amazing Mr Sorin; even after 7 years. very clear and understandable. Thank you so much

[@francismannion7075]

Sorin, every time I watch your videos I learn several new things. This video in particular is very helpful . I think this was my third time watching it and I feel my understanding increasing. Thank you.

[@LMCMaio]

You are a very generous man. Thank you for sharing your knowledge.

[@dekagfixxxer9269]

You are one of the best ,if not THE best, tech tutor out there! keep up the awesome work and maybe more smartphone videos?

[@YT7RR]

Toata cinstea si omenia domnu Sorin , eu nu ma ocup de aceste reparatii dar sunt electronist apropo de statii de RF pentru radio amatori , mi-a fost o deosebita placere a urmari aceste videoclipuri de a cunoaste cum functioneaza aceste,, smecherii,, care le avem in fata noastra de fiecare zi .Va doresc numai bine si spor la munca.

[@electronicsrepairschool]

multumesc

[@seagorman]

The most in depth easy to understand tutorial i've come across, very well done :)

[@NarasimhaB]

True

[@siddiquishoaib7929]

its great to have a teacher like you.

[@Mrcurlywhirly]

Great stuff Sorin - watching your instructional videos has been quite refreshing in this time of disposable electronics.

[@91oldman]

interet : ++++++ pedagogie : ++++++ sympathie : ++++++ dessin(drawing): -2000 yeah? Merci pour toutes ces videos enrichissantes

[@walterbutzbutic7622]

a kind generous teacher of circuits switch digital. i wish all teachers are like you. your the best Circuit master

[@shqiponjagv]

Thank you so much for all your videos. You are a very generous man. Thank you for sharing your knowledge, it will be most helpful. Keep up the great work. TRANSLATED INTO ALBANIAN LANGUAGE Ju faleminderi shumë për të gjitha videot e bëra. Jeni shumë bujar. Ju faleminderoj për ndarjen e njohurive tuaja me të tjerët që do të jenë shumë të dobishme. Vazhdoni me punën tuaj të shkëlqyer.

[@parisiadrian]

By far this is the best video from the channel and be sure that the other ones are excellent.

[@coldspring22]

Best video I've seen on laptop motherboard! Filled in huge gaps in my understanding. Thank you!

[@fixfaxerify]

Thank you for some great repair videos! Now that Rossmann spends most of his videos talking to his cat I suppose you can take over :) But I have a question, the first 2 mosfets, you draw them in series which doesnt make sense to me. First, if they were in series source would not be connected to source (with the same gate signal), second I don't see what purpose would there be in series connection here? On the other hand, if they are in parallel you increase current capability and redundancy (although if one fails as a short of course you lose control of current completely). Are they actually in parallel?

[@seckinseckin3919]

He already explained this. They work as serial mod, protection against shorts and high voltages, control battery charges sometimes. I quit watching Rosmann long time ago.

[@midnightrizer]

Thank you your channel is one of the best of it's kind.

[@Pandemonioum]

Hi! The startup chips is also known as super i/o chip? For examble WINBOND WPCE775CA0DG is a startup chip? Thank you!

[@NarasimhaB]

Thank you very much for this information. It is generous and godly of you to share this much precious knowledge without any inhibitions. I hope your good karma brings you many wonderful things in return. Thanks again for a wonderful video sorin.

[@bonbonpony]

From what I see, what you call the "startup chip" seems to be some general input/output controller with a GPIO bus to which all the buttons are connected to (like the "power up" button, the lid button, the "RF kill" button etc.), and it can also send on/off signals to different peripheral circuits to turn them on/off (like the bakclight, or indicator LEDs, or power supplies). The backlight is usually controlled by digital-to-analog outputs of this chip so that you could control the intensity of the backlight. From what I can see in the datasheets, it also has some serial bus interfaces (SPI-like), so it can control the keyboard and the touchpad. So it's basically an I/O port, that just "happens" to also control the power supplies. The same reason the BIOS is hooked up into it: because the BIOS is just a small EEPROM, and it has a _serial_ interface, so it requires a chip that would translate it to parallel data lines so that the CPU could read the program and data stored in it.

[@NarasimhaB]

That's very good info there.

[@sergelavallee913]

THANK YOU SO MUCH SIR, You are better teacher than my electronic teacher where i took my electronic diploma. You help me so much. I'll keep following you very very seriously. Thank's again, big thank's.

[@johannespersigas87]

sir you are the best teacher.. i learned a lot from you... please don't get tired sharing your knowledge...

[@seagorman]

Sorin thank you so much for all your videos especially your latest on PSU's & Motherboard, brilliant, will be most helpful, keep up the great work

[@jamilamameri2457]

Seamus Gorman ok

[@jamilamameri2457]

Pléase when i can get shema for laptop in internet give me pléase adresse tanks my émail [e-mail]

[@macoyespiritu8626]

Ive learn more from you sir. the way you teach and explain from any topic you prepared.. thank you sir.. keep it. were always waiting for your video tutorial.

[@benjaminbelobrajdic1074]

I have a question about not be able to change a battery cell. So what if connect bench power supply to the ends of a battery cell with the exact voltage of that battery cell. Does that mean we are able to disconnect the battery cell, without losing the data mentioned on a memory chip? I hope I was clear enough.

[@ernieschatz3783]

So, at 1:22:27ish you have all of this drawn out as simplified for demonstration purposes, but for example, at 10:22, the PDF schematic shows two MOSFETs with one of the MOSFET's drain connected to the other MOSFET's source. Also, it has the top MOSFET's drain going to 'Batt out.' The source on the other MOSFET is grounded. So with one MOSFET being on while the other is off, and the 'Output' taken from the point where one FET's drain is connected to the other's source, how are they interleaving pulses of the same polarity? Yep, I ran out of knowledge, LOL!

[@nateplotnikoff1197]

where do you get the schematics on the mother boards? I'm working on a brand new Lenovo ThinkPad P1 work station

[@musicstore2405]

i wish i knew a channel for mobile repair too.... you are always the best

[@melplishka5978]

Capacitors clean out counter emf and clean up dc pulses from noise.

[@The-Hidden-Trueth-6415]

This one has driven it home. Thank you.

[@richarddurose7153]

Very informative. One thing I don't understand - as the MosFET is acting like a switch, why do we need two of them in series? I don't mean in the power supply circuit driving the coil which is obvious why there are 2 MosFETs, I mean on the first schematic you draw showing the power management circuits from the 19V input and from the battery to Vcc.. Surely the Power management chip could connect or disconnect the 19V from Vcc with just one MosFET?

[@seckinseckin3919]

Disabling the dedicated chip and switch on the integrated chip means "Discrete to UMA" , you can search this like i texted.

[@seeingblind8]

These videos are great, thank you so much, Electronics repair school..

[@adnanbalkhi7969]

This is a very nice job ,,,,, as you said

[@AlvaroGomes]

Excellent thank you for sharing your experience, I loved the explanation.

[@rened4804]

Hello Sorin, so if you wire the Mosfet( Making a bridge) when It's dead the chip, would be doing its job base on the work of the second Mosfet I imaging? I hope I make sense...

[@alcadzbetz]

Thank you Sorin!

[@essambakhashwein]

May the Almighty BLESS you and your family

[@cameroonnationaleducationa7509]

And finally i must comment. I have been following you sir and i must admit i have acquired a lot of knowledge from you. thanks again and please don't relent your efforts

[@annyan904]

great explanation with practical examples.just one doubt.how to find a faulty ic?? and how to know which ic belongs to which section?.

[@DilnuwanAmaraweera]

Can I get this circuit diagram

[@marsmatics]

Very good idea and brilliant techniques! Thanks you so much for the videos.... May i have the pleasure of requesting on how to erase a SUPERVISOR PASSWORD on BIOS. Thank you so much!

[@boogerhead0]

12:00, this charger input has only 1 pass MOSFET. The gate is fed by a simple voltage divider which turns on the 1st, and only pass MOSFET . No 2nd MOSFET.

[@juliusvalentinas]

Great video. I suggest getting whiteboard and writing on it, or get a digital pen.

[@paulrockwell2644]

how can i define and fix missing parts like caps.??

[@mirosawjarmuzewski2405]

You are a true mine of information.

[@rebetli6]

Hi, very good video! Do you have similar about desktop pc motherboards also?

[@robertfowler9089]

great vid. very informative

[@giorgostexnikos4118]

that is for leesson to owers school bravo.....thenks sorin

[@grigoreman7198]

You are a very good teacher. Thanks!

[@rashh77]

Thank you very much.

[@menezesworld1221]

I learned alot from this video the explanation in paint that was too good 👍

[@s.kobeng1564]

I am enjoying your teachings

[@kamrannazarov5803]

Hey. I have a hp pavilion dv6-2152 nr Laptop is starting up normal. Power light is on , fan is spinning, but no picture on screen. There is only light in the back of screen. And this light is on only around HP sign. There is 19 v around screen ribbon cable. But where should I check for 3.5v (picture voltage-data voltage) Thanks

[@bonbonpony]

01:03:33 So they're basically a switched-mode power supply?

[@weerobot]

Mosfets are everywhere...

[@NarasimhaB]

Surprised to learn today that they are even inside the 🔋 laptop battery.

[@emmaanear7730]

is there 2 power button on this

[@zyggusbarasa8518]

Thanks for your educative videos

[@paulrockwell2644]

and i all most understand testing mosfets but not quite sure still???

[@radomirsokolovic2705]

Hi. Nice and very useful tutorial. I have Toshiba L650 laptop and two HP. Very good for learning. When I saw your channel and saw some videos I decide to try fix it. Problem is: Laptop works on battery (charged on another laptop) but not on AC adapter. That means that bios and startup ship (Nuovaton) works fine 3.3V supply is present and there are no shorts in any other supply. When connect charger I have short blink power led. On connected charger I have 19V on all supply's and on battery port. Only problem which I found is that first mosfet is short. I removed it and make jumper as you in one of your video. PM chip which you describe at the beginning of this video I did not found on motherboard. Only what I found is chip which control battery charging. Any suggestion where to find problem. Also have another two laptops HP with i7-6600 CPU which is soldered to main board. These two do not power at all. When connect charger CPU is heating a lot. 3.3 and 5V supply is present. Power button 3.3V is present, Bios 2.9V startup chip ENE KB9028Q 3.1V. Under CPU there are a lot of capacitors or coils not sure wnich one which are short. for coils it is ok? but not for capacitors? 19V is present on all supply which I found. When connect battery CPU or chip-set do not heat. Previously present power supply 3.3 and 5V are not present anymore. Power button has 3.2V. How that possible? Is there two 3.3V supply? Bios do not have 3.3V on pin 8. Startup chip has 3.3V. When press power button 3.3v and 5v supply starts and disappear after 5-10 sec. I do not have a linear power supply which you use in your videos. Only digital multimer :( so can not check for shorts as you.

[@jeanedouar1971]

are you counting the leaft over days to live??

[@paulrockwell2644]

thank you you are best teacher ever

[@warrensworld3]

Can I replace a laptop power management chip if I buy the same type chip and model number, or would the new chip need to be flashed to work. Thanks

[@donald1056]

Where do you get schematics for motherboard - been trying to find - can't find any

[@coldspring22]

just google for the laptop model number and "service manual" or "schematic". You can often find one. Sometimes it's only available in some Russian or Chinese website, and sometimes you have to pay for it. But it's much better to be able to fix laptops without schematic if you can do it!

[@cyberleoj]

Sir.. good day to you.. if its not to much,, can u share a copy of that pdf youre showing?.. thanks i really like your channel.

[@rannyday2635]

How can I tell if the bios software has errors (needs to be flashed) or keep troubleshooting for hardware fault (short or bad cap)? Dead pc no power light@?!

[@francismannion7075]

I am really enjoying this lesson , it is interesting and very informative. Thank you.

[@netcomsolutions369]

good day sir, where can i get laptops schematics plz?

[@terrywatkins8553]

A great Lecture, good on you

[@kasulejonathan2145]

how can the mosphet be soart on ground

[@reggiekamau9865]

very nice.this guy is good .really good and teaches really well.keep up.

[@enteranon3342]

What were nice if you could make a video of how to test individual components for functionality.

[@yaserhumeid3922]

Your videos helped me a lot, hope you get more subscribers and viewers greetings from Jordan

[@computersrepaircotesaint-l7407]

Dell Latitude E6430 no 3.3v on the power button even if I turn it on. once I turn the laptop on its working fine but still no 3.3v on the power button. I can't find the 3.3 volt that power on the laptop. Anyone came across this problem plz help

[@alekshernandez2]

he mentioned on a video, check the center pin of the power adapter from AC

[@glazyrap9244]

i have a x550cl wich had liquid damage and i solved that laptop start but its black screen... i made measures but i suspect to be integrated rams, what you think?

[@binh4779]

Nice explanation. Thank you

[@paulrockwell2644]

i need you fix hp 17g pavilion find out ho to really fix them

[@mshone1972]

Great job, thanks !

[@leggat2000]

i like you when you speak i can understand easily thnks

[@RicRic-bg8sn]

Hello greats videos Sir ! want to laugh ?? a friend gives me his Emachine pc with no screen and no boot at all, only led and fan working... So i check everything , the charger port, the mosfets, the capacitors etc... 19v ok, 3.3v ok 1.5v ok etc...testing rams, do all the millimeters of the motheboards during 3 hours, nothing wrong on my mind... and i finally get THE idea to check ....the battery cell 3v....it was at 0.7v only !!!! so quick replacement with a fresh one, and now...Boot, screen and everything perfect.... Your video was fine to train me for such real cases , and i thank you so much for that! The best is to come cause my friend had given the laptop before me at repair shop , and the technician said to him (after 30€ testing fees)...Motherboard is HS...and in the same time he lost 4 screws, and warped one of the support for the keyboard wich was out of the rail. Have a nice day, cheers from France ;-)

[@hugoboss7600]

Why u not took out the battery? , without battery laptop needs to work ,ask Sorin...

[@TonyoTorres]

i would like to know if you got a fix video where a schmitt trigger gets involved, Thanks for all your videos Sr

[@thetiredtechie2704]

I love theory, thank you!

[@electronicsrepairschool]

thats why u r tired :))))

[@thetiredtechie2704]

You may have a point there XD

[@deanxaka]

:D

[@mark-d9k9b]

Thank you; good stuff!

[@villeurbanne]

The Best of the best 👍👍👍👍👍👍

[@DimiCavaro]

thank you very much for the knowledge that you share with us is very helpful keep doing what you do at make easier for as the begginners to learn,thank you again!!!!

[@zulkarnainkarim]

superb sir....thanks

[@dragonlard4595]

This is extremely helpful video. Thanks

[@federicopalima9980]

Good day to you sir, thank you so much that ive learned a lot from your video explaining on how to repair a defective laptop but can you please teach me how to reset the bios password on my asus k401J laptop...I am very much happy if you can teach how to reset ...thank you and more power...

[@yehtut3209]

many thanks, sir.

[@redquinto1412]

thank you we learn a lot. keep it up teacher

[@dongkoy1978]

great video tutorial sir, im glad to see your site so helpfull

[@hammershigh]

What if the batteries is never detected? New or old, makes no difference.

[@pettahprize6114]

Thanks sir,

[@jeonandrew9472]

thank you .most i want for years

[@ziadfawzi]

Thank you so much.

[@saarike]

Have ever meet a broken bios chip or reprogrammed faulty bios-chip?

[@electronicsrepairschool]

download the bios image, copy to a usb stick, plug the usb, keep pressed the 'b' key or the 'windows' key and u should be able reprogram the bios chip

[@saarike]

Thank you very much sir! So I don't actually need bios-programmer?

[@electronicsrepairschool]

depends of the laptop, if is from 3-4 years old, no

[@electronicsrepairschool]

but do your own research and let me know

[@saarike]

Ok! Thanks. :)

[@geojor]

just great, thank you ...

[@taimoorkhan3726]

Any one know from where download free schematic for laptop