About the motherboards .... (part 1)

[@klwthe3rd]

Sorin it is because of videos like this that so many people have great respect for you. Your explainations to us viewers at the beginning of this video was very understandable. We don't just look at you as a great technician, thorough teacher and all around great guy; but one we can trust to tell us the truth. I have never met you but I feel you are one of the most honest men in the world. The stories you tell us have such great wisedom and knowledge that we can't get from anyone else. I really appreciate that you share so much with us. Both professionally and as a friend.

[@rayofcreation3996]

Kenneth you've put in words what so many of us feel here. Its people like Sorin and their generosity that makes life bearable and enjoyable on this planet right? Way to go. Good luck to you.

[@albertcarlos1674]

I recently join this channel..Only to realize there a pple like you Who fill my mind with advanced electronics.. You are super my mn..only geographical distance is the barrier.. GOD BLESS YOU WITH SUCH UNIQUE LESSONS

[@srejth]

Dedicated work within the time limit of 4to5 complicated laptop repairing and mobiles and giving information to staff and returning to the teaching video . We all thank for the camera, microscope toggling and power supply, mulitmeter, ammeter on the video corner for the valuable information atonce. You are a great man for the world......seeking 4 electronics...,.thank u.

[@solswed]

Thanks to you I was able to bring to life my dead Dell spx labtop . Thanks for sharing you knowledge.

[@runthomas]

i live boring life now...and this man has made it exciting again...im hungry for knowledge and kicking myself about all the laptops my family friends and girl have thrown away .

[@ultrashock3202]

This is the simplest and best teaching I found on youtube, a great job thanks.

[@creativitydesign4947]

Fantastic videos, great for learning. I have just recently come across your channel and is already one of my favourites.

[@randgtechnology]

Thank you sir. This was not even told in schools. Simplified explanation.

[@rizwanshaa]

Sir, first of all i am thanking you for your vedios. i am watching these related field vedios for a long time. but i catch your one recently. ur vedios amazing, , because you teach the real time experience and further more its very clear. i want to add some things here. i noticed when you explain , if you can give some information on the theory part and do the practical part, it will be more use full. i need more vedios on iphone repairing, the basics, and fault finding. very good teacher you are.

[@Electricworld-1]

Out of all of KZbin videos you are the best I have seen, i have downloaded all your videos , thank you very much for your help, i wish you all the best my teacher.

[@obbymiles277]

Am doing great because of the knowledge i had from your lessons sir. I can fix charging problems for laptops just by following the 19volts line pass as you just showed us easily. I call today's lesson as GENERAL DIAGNOSE OF ALL POWER SUPPLIES ON A PC MOTHERBOARD. I came across a HP 840 misbehaving i believe the 3.3v power supply on bias is not working ,i will give the feedback on comment. Thanks sir

[@rduwe9466]

Very educational video, not one on all youtube can even remotely tip on you. i have a degree electronics and learn more in your videos then all the time i sat on the schoolbanks. I you like and if you find the time could you explane about all the writings on pcb boards and motherboards please there is so much information on there but i have no clue what it means. Thank you for all the great lessons.

[@theobuiatti6420]

Sorin you need to start using boardview.. In 4 seconds you will find your 3.3v 5v 1.2 or 1.3v In the boardview is easy the see the network of the ic and just pointing to a pin of the bios ic in you case 3.3v you will see were the 3.3v started and the ramifications.. Now a days is easy to find boardviews of all most all big board producers. Just ask next time I. Got 1tb of schematics and boardviews You number one fan lol

[@timidijamesodubo]

Please how do I get laptop schematics, I need som please thank you

[@theobuiatti6420]

vinafix.com/ and google is your best way to find. make services free and paid. just make some effort and you will find everything

[@rened4804]

Could you show us how to do it?

[@rened4804]

Could you show us? how to do it? thanks in advance.

[@aneezaliyar1901]

39:18 😂😂😂 How you understood what im thinking.. 43:12 Why i choose this motherboard, its old one... 😂😂 Anyways its a very helpfull video for me. And thanks a lot for your effort to enlighten people. Again thank you master. Keep up the good work.... God bless you.

[@anselmeahlin4195]

actually sir ,the voltage going on the bios chip is called an LDO voltage n is supplied by the pin number 8 of the standby ic (tps51125) n the 5v from pin number 17 before u get the actual 3.3_5v coming from pin 7 n 24 .the LDO is also the voltage u get on the power button .

[@AwsmBuff]

I have felt my brain growing watching this video and googling things I did not understand at the same time. Thank you so much! xd

[@TrafalgarLawHeart]

You know what sorin, all your video is really informative.. im learning alot. i just have abit knowledge about electronic. but all your video make me learn alot of things.. u are best teacher ever.

[@TrafalgarLawHeart]

@Andrew_koala cool. thanks for the reprimand.

[@EBRIMA-cz6io]

i am an electrician but i like the way you teach people on your chennal

[@saarike]

This was really good video! I tryed about 1 year ago to repair asus laptop, which the problem was, that it power light turned on and fan was spinning, but the screen was black. It went horribly wrong when I measured with a little knowhow voltages from various places, there were 19V and 1,8V present. When I measured voltages from resistor network (it was mistake) my test probe shorted 2 pins from resistor and it caused more problems. Now there is shorts across graphig chip's very small capacitors. And also across some other ceramic capacitor. With this video and others i know now a little bit more about motherboards.

[@electronicsrepairschool]

Great, I will keep a eye open for a asus with black screen

[@saarike]

Ok! Keep up good work. :)

[@segumohideennafeer2678]

Great I confident to repair Laptop. Thank you. What is your brand of multimeter that you are using? Top

[@mehmetedex]

THESE ARE SO EDUCATIVE so keep 'em coming

[@WHPSCrew]

i'm going to have nightmares about not being able to find mosfets after this video. thanks sorin.

[@Martin-ot7xj]

hi there , at 20:57 you are spoke about power supply , mosfets are power supply?

[@thetiredtechie2704]

"Where are my mosfets?" should become a shirt.

[@electronicsrepairschool]

:)))), i will order one :)

[@thingshappen9199]

@@electronicsrepairschool Sorin, please can you tell me the name of the black tape at 12:40? I've been looking all over to buy some but i can't find anything because i don't know where to get it nor the name. Thanks.

[@fareselamine8115]

@@thingshappen9199 Not sure if you're still looking for that, but the closest I was able to find was this: www.amazon.com/gp/product/B01E8W9XEO/ref=ppx_yo_dt_b_asin_title_o06_s00?ie=UTF8&psc=1 I've used it on several laptops and they seem to work perfectly. Hope this helps!

[@jeramsadventuretv4905]

Thank you for this video sir. I keep on watching again and again just to understand every details of it. I wish i had your talent on how to fix motherboard easily.

[@rayofcreation3996]

Dr. Jack I'm sure your passion and interest will provide you with all the skills necessary and you will be able to troubleshoot like a pro. Sorin is a great inspiration. Good luck to you.

[@pierdolio]

You may know your stuff really well and can relate your knowledge to people who are experienced but not to “newbies”.

[@NarasimhaB]

That's great. I wouldn't want to be here if it were for newbies. I'm trying to gain deep knowledge about electronic circuits, motherboards and power rails. There are many newbies electronic channels like linustech where you can find info about basic electronic things.

[@sergelavallee913]

Thank you, you are so good. I learn so much. Keep your wonderfull job. We need people like you, the best of the best.

[@catharperfect7036]

My biggest problem as a learner is getting old motherboards. Everyone wants surprisingly a lot of money for them, even when broken. Like AUD$50 each.

[@org4ngrinder]

Thank you for for talking about the differences between shops. It's hilarious listening to kids who have done 5 computer jobs in their whole life and average 1 per week talking about how repairs should be done. Good luck surviving anywhere other than working for yourself with that sort of flow. Talk to someone when you're handling 25+ jobs a week.

[@victorzedwings]

that NEC low ESR cap under CPU is often faulty after couple of years. MOBO wount start. Hot air test it. Replace it with 4 tantals and 4 ceramics suitable for this power rail.

[@rashh77]

Thank you a lot. I watched part 2 before part 1. Awesome.

[@vlatkosurlan545]

That scene when Neo has Kung Fu loaded into his brain - watching this channel does the same thing. You learn electronics Kung Fu on steroids.

[@deividaskevisas9823]

Thats a good one. Best thing i like is he says most things in detail like which bios pin, what mark means etc. I would like to know more about ceramic capacitors, how to identify, how to replace and which to use, how to know the pole etc

[@rolandberendonck3900]

@@deividaskevisas9823 They have no pole.

[@deividaskevisas9823]

Thats a new one to me lol i do that stuff rarely, so i dont know much

[@mikem4432]

great video, not sure I know when your using the multimeter or the voltage probe, would help if you labeled them or mentioned it as you work.

[@meineroteBlume]

Thank you a lot! Your videos are great! I fixed my Lenovo Laptop. Your explanations are the best

[@bicepius]

34:36 These Samsung boards have common problem with big NEC Tokin capacitor under CPU that goes bad, which makes the laptop turn off randomly.

[@mshone1972]

Not only this boards. The same is on most MSI laptops and some of toshiba models.

[@vighneshkumar2603]

Me too got a Samsung lap which is NP-R522, i have removed it with 330 capacitors and issue got fixed. It was very difficult for me to remove that boxed capacitors behind the processor.

[@mohamenfis6854]

thank you so much good job we badly need practice your friendly method is wonderful very vivid ,not like others who give a cold speech like an answering machine i feel like i am besides you in your workplace

[@rayofcreation3996]

Moha Menfis you've said it absolutely well. I completely agree with you. Its what gives Sorin's videos the touch of life. You feel so well connected right?

[@andrewfish1117]

great vids I'll be a patron when back in work

[@mihaivioara]

guys change the playback speed to 1.25 in video settings... you`ll thank me later

[@quebonitoeslobonito7358]

@@mihaivioara I went 1.5x lol thanks

[@beogeek]

I love this man, kudos to you Sorin, appreciate your work mate.

[@mihaivioara]

Thank you for sharing your knowledge Sorin! God bless you 🙌

[@CueloVsLabay]

Thank you for uploading this video. I wish i could dive deep more into electronics, may i ask where should i start studying. thank you so much.

[@Saad-Zulfiqar]

Can somebody explain me at 32:19 ?? what does 0.0 v on multimeter means ??

[@MrOwl1985]

I dont understand something: Why do the manufacturers sometimes place the first MOSFETS so far away from the charging port? Doesn't it make the whole design of the board more complicated to have to route the power up and down all over the place like that? Wouldn't it make more sense to place the first power distribution point closest to the port? Please correct me if the question is completely invalid.

[@xen00x]

Just perfect! Thank you so much for your explanations! It is very useful as a beginner!

[@husseinelwan9682]

i always wanted to thank u , love from Egypt.

[@electronicdiy8544]

Repairing without schematic you are real pro.

[@PaulHigginbothamSr]

North Ridge Fix finds the board shorts with his diode mode. He just searches the board till he finds no 1/2 volts to ground. When he finds no drop he knows where the short is. He has a thermal camera and he finds where the heat is by putting more and more amps at 1.3v, upon removing that chip, if diode mode finds no short he has the fix.

[@khalidzorro5410]

Thank you so much for all Respects

[@محمدسيد-ع4ي1ح]

it is a fantastic lesson i jUst have one question how can i locate the GPU CHIP IN ANY MOTHERBOARD

[@sandislancmanis1178]

46:56 min what wire you are using to make connection ?

[@electronicsrepairschool]

normal copper wire, nothing special

[@McMallister]

I bought copper wire but they are not conducive, why?!

[@corsodipiano]

@@McMallister en.wikipedia.org/wiki/Magnet_wire The copper wire are conductive, may be is magnet wire with a little coated isolating

[@Faheemaffiliates]

There are 3 section in power supply 19v 1 Adapter V - in supply to 2 fet 19v coming from main fuse which connected with charging section and discharging section . And Step Down section which providing 3v and 5v . But from main fuse 19v providing individuals supply as I/O Ic and GMCH, ram section , ICH , and Step Down section.

[@basreeishak4084]

Your tutorial make me understand more about motherboard, great job sir.

[@easypipsforex4741]

Same as Me........Thanks Alot too

[@SamirJunaid]

The beginning of the video was so good, especially explaining the power supply parts. But later I got lost, I don't know what's going on, and how he can find where's the problem?

[@umagardeholly6036]

The best practice I could ever have, from you, many thanks to you, seriously ! ;)

[@ellieokeefe7742]

you are a great teacher keep videos coming A*

[@viktork3390]

Ez nagyon hasznos volt, köszi!

[@Gli53]

Thank you, for sharing your knowledge, the video will help me to understand better the process and troubleshooting motherboards.

[@wayneollerenshaw2900]

love the work you are doing 1 question what tool are you using for the amp/volt/current you use it on mobile charging keep upthe good work

[@dawitgetachew9528]

how to fix cpu area all ceramic capasitors short reading in multi meter help me?

[@jaybienicedahili12]

very nice sir.. thank you for teaching us here in your youtube chanel.

[@Martin-ot7xj]

what meaning of beeping? whenever we set multimeter on diode mode beeping means we are connected together?

[@anselmeahlin4195]

but i so much like the way u diagone the faults ,is so satisfying

[@herbertramos5873]

hello KUDOS to you Sir... Ive learned so much... thanks for sharing and teaching us... God Bless You and More Power...😍👏👏✌✌👍👍

[@offroad2024]

HELLO YOU ARE MY ELECTRONIC LEGEND!!!KEEP IT UP! CAN U TELL ME WHERE IS THE VCC IN THE MOBO?

[@jimgill8193]

I have a aspire 5742z with battery in the gets so hot you cant hold it and laptop turns off . but can take the battery out and have wall pluged in it stays on and dont shut down. does that mean that battery is short or chip may be shorted

[@acrossphilippines6338]

nice video..thank you very much...just want to clear something, which probably a noob question ...i am new to laptop board repair..,,just want to ask...when testing the power supplies of the laptop..all ceramic caps should have voltage or those only with coil and mosfets...and you list down for me, if is it ok..the voltages need to be test..like what you said 19v for the power jack all the way to the capacitors and 3.3v for the bios, 5.5v i think for the USB and 1.5v for the RAM. is there anything else...sorry for the question if annoys you..thank you very much again...big help..

[@SechComputers]

Hi pls I want to ask if the CMOS battery is on the board is it possible that you will the exact 3.3v

[@3aeren]

huh?

[@morphuk1]

Yet another fantastic video. I understand that the 19v rail supplies all the other power supplies on the board. However, on the other power supplys, is there some sort of step down voltage regulator to drop from 19v to 3.3v, 5v etc on each individual power supply?. Many thanks!

[@okejee3455]

Ade B each power supply will change voltage output as designed. To understand how this is done, study how a switching power supply works.

[@saysles]

No no. The purpose of the mosfets is to set the lower voltages by adjusting the pulse width modulation on the gates. Ok?

[@Bhabaparernaiya]

Lovely video Sir...the way you teach i like that.its awesome.thank you for sharing your experience.

[@zapatobama8301]

is it only the power supply or start up chip which has 3.3v on the board?

[@ANACONDA_2000]

does the fan has to work all the time or it works time to time when there is a heat?

[@electronicsrepairschool]

most of the fans are linked with the processor temperature sensor

[@shahidkhan-mb8rm]

great work sir . and thanks for the video

[@jaefoad3331]

Why does the multimeter pin burn the mosfet when I’m checking voltage

[@respuestasbiblicas7634]

Hi, I've seen your videos and they are really helpful. I have a burned motherboard and I tried to check the power of 19v. I hadn't started my test when I accidentally touched a coil power supply and almost burnt me. Does it mean that coil is dead or I should look somewhere else? Thank you

[@AkiraReyna]

thank you so much..I really learned something everyday from your video..stay healthy and more power..I'm excited everyday waiting and watching your video..thanks alot again..

[@bonbonpony]

16:16 I have this issue with one of my laptops right now: when I disconnect the charger, the laptop starts making high-pitch noises, like a connecting modem or something. I think it might be some voltage converter, but I don't quite know what might be wrong and how to fix it. The laptop is working fine (I'm currently writing from it, so yeah, it's working :J ), but these noises are probably nothing good, and it may break one day because of that :q so better be prepared than sorry.

[@Marko_Djuricic]

I think it's actually some aluminum elecrtolytic capacitor from battery power rail since you said it starts making sounds when plugged off.. If you dont want to mess with it, just remove the battery and power the laptop just from the charger.. If you want to know what it is, open the laptop and listen to where the sound is comming from when you disconnect the charger..

[@bonbonpony]

OK I fixed that issue a while ago. It turned out to be a bad charger. The sounds were actually coming from the inductors on the power rail when the charger was connected but the laptop was not consuming power (e.g. turned off). It ran fine (and silent) from just the battery. So I measured the voltages on the charger and it turned out to supply only 6..8V instead of the expected 20V. Actually, it supplied the 20V, but in thin spikes that averaged to that 6..8V :P Hence the noises when the charger was connected. And it worked fine thanks to the battery that somehow charged fine from that crazy voltage to its full operating voltage and smoothing it out for the laptop to run. When I disconnected the battery and tried to run it just on the charger, it didn't want to start at all, just flashed the power LEDs and turned off. So I replaced the broken charger with a backup one and now it's working fine, with no weird noises coming out of it :)

[@bonbonpony]

There's another problem, though: when I was cleaning it up (according to the instructions in the Hardware Maintenance Manual from the manufacturer), after putting it all together I noticed that the screen is blank :/ However I can see the contents of the screen when I look at it at a certain angle with good light shining on it, so I guess the backlight is not working :/ I checked the LVDS cable line by line and it's OK. I checked the fuses on the motherboard and they're all OK too. I checked the voltages on the LVDS port and they also seem to be fine, 20V going to the backlight lines, 3.4V to BACKLIGHT_ON, etc. But the backlight is not working anyway :q Any ideas? I suspect the inverter, but I don't know how to check it. I don't have shematics, so I don't know what voltages should I expect and where to measure them.

[@Marko_Djuricic]

@@bonbonpony Well my guess is a cable since you said this happened after cleaning (not your fault but you moved the cable while cleaning). Try flexing the cable in every way, see if the backlight turns on.. It can also be the backlight itself, can also be the GPU, sometimes it acts like that, or the inverter like you said but like I said my guess is the cable..

[@imonw3b]

Hi Does anyone know's the model of second board please? Samsung? 34:34 mins Thank you.

[@imonw3b]

Look's like Samsung RV510?

[@Brison1949]

I admire your patience...

[@electronicsrepairschool]

Thank you :)

[@albertcarlos1674]

Really true

[@dongkoy1978]

hi sir thank you for a great video, i want to ask how to check mosfet if it good or bad?

[@electronicsrepairschool]

if are not in short, are good

[@dongkoy1978]

thank you very much for quick reply sir :) , you are a nice teacher

[@whoisme678]

The samsung board looked like an NP R530. ? I am not sure it matters whether its old or not as it shows people like me how you arrived at solving the problem. Well done.

[@kamarakoly2171]

what i want to know is if we can use the same methods on central unit motherboard if not coud you do a video about that by the way thank you for your videos you're the best thanks of you i'm a monster of repairing laptop now

[@vighneshkumar2603]

Hello sir... you are so great... i am following your all your videos.. its very interesting and knowledgeable, thank you once again. I have 2 doubts, if you could please help me to clear it.1. How do we confirm whether the BIOS is not working, any symptoms or checking points etc.. even after there is 3.3V and 5V ?2. How do we confirm controller chip has issue?

[@morphuk1]

Another great video but i have a question !. You state that the individual power supplies have mosfets, coils and capacitor. can i ask how the individual voltage rails are created?. I know it all originally comes from the 19v rail but how is it stepped down to the smaller voltages such as the 3.3 or 5v? Does each power supply have its own transformer (or multi tap outputs from the primary transformer) or does each rail have its own voltage regulator IC or is it some magic involving the mosfets, coil and capacitor only ?

[@dvgog]

Ade B Look up buck converters

[@antoniojesusarquillosalvar4342]

You are the best. Greetings from Spain!

[@williegreenway5464]

Is Mr. Sorin saying Path as Path or Pat as in Pattern when he discusses the power supplies? Thank you...

[@ciulindragos798]

Foarte frumos! mulțumesc!

[@andreamodiano]

Your videos are excellent, thank you.

[@RealSourceryd]

Sir , a smd capacitor is usually brown , but i have seen small smd component which is white and it’s very small component. I was thinking it was a capacitor but when i test the resistance i get mega ohms .. so my question is what are they really , i see them on many motherboards ? I was also thinking it might be a fuse then i noticed that they are sometimes in parallel or in series. Thus it’s can’t be fuse as they won’t place fuses in such ways.

[@techmonster2632]

any 3.3v well come from ic chip , normal power supplies circuits dont gives u that voltage

[@johnhiggins9020]

Would you be the east European Ray Liotta with a soldering iron as a weapon

[@reboot1337]

what if power button gets only 0.5v ? obv i tested board with weaker AC adapter, can this be a reason get lower v all over the board ?

[@orange11squares]

no, you should always have 3.3V on button, no matter what.

[@reboot1337]

@@orange11squares i still wait right AC i will do more testing, bought broken laptop from ebay for fun, but main AC was dead.

[@2368rafa]

A question, in some cases the KBC bios or if it carries PCH, can also be corrupt, can you clarify something about those cases, please. Thank you.

[@jundeguzmanjr.301]

your the man sir,,,i watching your video i learned a lot of you.keep sharing boss

[@عامرالساعدي7616]

The vots 3.3 & 5 exist in around ic charg but i see in that mosfet 13 volt

[@pouria6586]

I rarely comment on videos but maaaaaan this video is awesome

[@junhanggodlaviosa2493]

greetings from the phillipines... sir.. thanks for the video...

[@burt591]

You are awesome man!!!

[@F3rnando666]

This is golden! Thanks!!

[@rokrjock33]

Hi' I need some help and was hoping to get some advice as I can see you are a very experienced professional. I have a Legion Y520 by Lenovo, it was 3 days ago while playing a game called dying light my laptop suddenly shut off. Since then it is not turning on neither is the charging light turning on when plugging in. What I found checking with a multi meter is that the battery has 11 volts plus left but if I plug it into the board and check at the connector it shows me .02 or 0 volts. The power connector has the correct voltage which is approximately 20 volts. I have been watching tour videos and wanted to start from the first one with regard to laptop repair. Just above the power input on the board are what look like two mosfet. The first one shows 19 volts on one side but nothing on the other and in beep mode it beeps if I connect the probes to both sides. The mosfet or whatever it is next to this first one is not getting any input and obviously no out put. On connecting power to the board the first one gets burning hot and the second one does too but not as hot as the first one. These chips do not look like a regular mosfet as i have seen in your videos and looks more like those BGA chips and components. There are no legs like the ones in your video but there are small dots which are on the edges of this component which is where I took the readings from these are both just above the power connector on the board one after the other moving upwards. There are a few capacitors the small aluminium types and they dont show any power at all. Could you help me identify the tracks and components or confirm that the one getting hot is the bad one because by looking at it and its edges I can see the effect of excess heat like the area around it seems like it melted and then got back to normal. I tried the troubleshooting steps like the static discharge with both power and battery, then each of them individually and even the bios reset. All I found on the net on Lenovo support was that they changed the motherboard in most cases with one saying he was told it is a motherboard fault and will take almost a month to be sent where it'll be repaired or replaced and sent back, but when he left it with them they called him after 2 days to come and get it as it was fixed. They told him it was a bios issue which is quite strange but I hope you would know whether it is possible to be a bios issue which isnt letting the laptop even power on. How would I be able to flash the bios on a non working board if I want to see if it is the same case as they told this guy which was not letting it start. It is a really expensive laptop here in India starting at around $1100 and I have the core i7 7700q model with 16 GB of ram, nvidia 1050ti 4gb graphics, a 512 gb name ssd Samsung evo, a 2 tb sshd, and windows ten. I can send you a picture of the board and have the schematic file but it doesnt show the board like I have seen in schematics for other electronic products or gadgets where it is shown the way it is laid out and components are labelled and marked in their respective place on the board. I look forward to any help I can get and will be grateful if you could tell me where to start watching your tutorial videos from. I just know the basics of electronics I would say bare minimum and have some experience soldering as I made some projects using components and some arduino projects too. But I would appreciate any info I can get as I consider myself a total noob. Thank you for reading this. Regards shantanu

[@bonsurichard4641]

sir i have a laptop when you press the power button the the switch light comes and go. now if you press the button you can test for 3v and 5v but it does not stay on. there is no schematics for the board.