Important! Steps to diagnose a faulty laptop 

A magic short with proper calibrated tweezers and everything went back to normal that's magic and that's what i like about this channel not just replacing components from donor boards good job

You man makes magic in every video you post...a proper calibrated fuse, a proper calibrated mexican cigarette, a proper calibrated tweezers, but the most important thing....A proper calibrated brain. Thank you for all your videos Mr. Sorin

The gate of the first mosfet is usually controlled by ACDRV output from battery charging IC. For P channel mosfet to turn on Vgs must be negative meaning the voltage at source must be higher than voltage at gate. Had a similar issue, sometimes the mosfet would turn on and sometimes not; it turned out to be a dry solder joint at the gate.

I cannot say thank you enough for your videos. Keep up the great work... your videos have reached the islands of Trinidad and Tobago 🇹🇹...

it was one of your best tutorial videos , this video absolutely for beginners , your explanation was very simple and easy to understand , please upload more like this videos . thnx

P channel MOSFET lets power through when voltage on gate is LOWER than source. ● N channel MOSFET lets power through when voltage on gate is HIGHER or equal to source

"You see? That's Magic!" Amazing, Sorin Thank you, as aways.

Great video Sorin! Respect for the guy in the background doing push ups :D 07:09

For beginners, this might be magic. My only advice would be to check if secondary rails have no short. Laptops have Step-Down Converter ICs that report PGOOD signal to the Embedded Controller and then tells the Power Management IC to turn on or off the Protection MOSFET. If a high-side MOSFET let's say in the CPU VCore is shorted, it will GND the PGOOD signal so that the Power Management IC will cut-off power from the Protection MOSFET and prevent the 19-20v going directly to the CPU Vcore (1 volt) and frying it. What he did was bypass this protection and activated the Protection MOSFET, he was just lucky that it wasn't the case with shorted secondary MOSFET. Sorin probably knows this, but beginners like you are going to make that mistake.

You are one of greatest technicians on RU-vid I enjoy watching your videos because it help me so much

Best Explaining Video for this year. Great work Sorin 👌.

You have the magic touch. Thank you for your video. All the way from Mombasa Kenya

Fantastic Sorin you make a good teacher 👏

🤣🤣🤣🤣🤣🤣🤣🤣🤣 "Magic, in life there are things not worth asking" truly you did my day, thanks for this,

You're a great Teacher, Sir.

What would be good is if we could get a proper explanation of the purpose for and how this configuration of MOSFET pair works, including what drives the gates.

You’re really magician, nice video Sorin

Sorin perfect diagnose. I do it like you. so I understand now what to do. And what it suppose to be doing. When a laptop is dead. And i have the time to look up the problem.

Thank you for sharing . Keep the good work

You removed the battery, but you didn't drain the residual voltage by pushing the power button for several seconds, Sorin. Maybe this was the cause of having no difference removing the battery...and this "magic" is almost always microcode-related; in other words, BIOS and/or EC. You know very well they became corrupted (specially in Lenovo ones). By shorting the gate of the 1st mosfet to GND you leaved it in an ON state. That's why mosfets are not like bipolar transistors (as you correctly said in the video), because of different parameters, like capacitance. And that's why is sometimes difficult to chech a mosfet with a DMM in diode mode, specially the high current ones (>60A).

Hi Sorin , it was me to ask you that question about which pin we have to short !!! thankyou for answer my question . keep it up

Thank you, master Sorin!!!!

you answered, some of my lingering problems. thankyou

Mr Sorin you the best teacher,(in Indonesia, anda guru yang terbaik Mr Sorin), thank

I like your style man keep it up.

I always learn something new here!

nice to see you teacher👍

thank you mister sorin , the problem is a frozin bios that is make the first mosfet is not open , but when you make a short to gnd you ar making a kind of seliution , if you ar not making a short to gnd for a 1st mosfet and making a reset the bios it will work too , thank you agen

The W.W reference was right on point 👌😁

Thanks sir, u always go to this topic, very important yh...

Very very interesting ! thank you very much...

Know how and entertainment. Thank you.

genius!! thanks from argentina

Nice repair video

This Mosfet is a hero!

best video for junior or diy

It is truly magic

Hi, I love your videos

Very nice sorin....thanks....i wonder is it a bad cap somewhere?is it possible?

"It's not a frozen bios, it's actually a dead motherboard *Sorin Laughs*" While all viewers are worried XD

Thanks!

thanks Sorin!!

Fantastic

Sorin I think we should have 6v at REGN pin . This mean we should a voltages at the gate = 19+6=25v at AC DRV pin. However this is true for some laptops where the gate are connected together. 25v is required for such MOSFETs to drive power. Think from this idea see where the 6v come from. Thanks for the video God bless you. I'm Ronald from Uganda

The Cmos is not shorted but perhaps partially leaking , that would explain that on second trial it was only 4V, i guess , when you was shorting the gate directly to the ground, you may have killed the driver output of the power IC, that would explain the sudden working with a weird voltage ... I don't actually like such test, better to use a resistor to avoid direct drop down.

This video should be called "Sorin and his Magic Tweezers".

👍nice to see you

An elegant testing to identify problem as mosfet gate. Where I was lost to suspect battery, also ram. Without fan, high heat level a change to inside case as power on? A unit without battery as bios enable, that must load bios from power supply as battery + charging port to 19.v. Super IO as tree to supply laptop as checking memory and loading OS from drive. As shown to battery removed, reset...the problem was gone. But will it return? Is this a common fault to the model? At the customer, they would perhaps be angry if the fault returned after some series of end use. So problem. Charge little money and warn the customer? Replace the first mosfet with fuse wire? Test the laptop after several hours of operation as working on/off. Explain that the Toshiba manufacture was cheap, likely to fault repeat again and again? A tricky place to be as repair, customer as happy. M.

Sorin you are a hero :) plz let as know how to tell if a mosfet is p or a n channel ! Let as c you doing some push up

büyük ustasın aga helal olsun sana yardımların için başarıların devamını dilerim türkiyeden

Good job 👍👌👌

imi plac foarte mult videoclipurile pe care le faceti

Super! Thx :)

Watching here sir sending full support

hi, i see your videos and understand most of the concepts (i saw a little of electronic concepts in university) but, where to start to recognize all the components like you do on your videos. I really apreciate if you tell me lectures or links to learn more about the components

Nice one

How weird 🤔🤷🏻‍♂️ but great job Sorin, as always!

Why do you get a 0.6V drop between charger + and ground if it is good?

New Tshirt “MOSFET IS A HERO” 😎😎

Sir, You know we used to degauss old CRT monitors for static remnant magnetic field. As an IT technician I call it like; You just degaussed that mosfet. OK. Lets call it re-volted OR defibrillated.

i think we have a 19 Volt Zener diode in that mosfet also contains a capacitor. In this case, we can discharge the charge and return the mosfet to its original position, then the laptop will work. There is no luck.

Stiller Good job. But how you remember what you did exactly on just repair cases in case of return . You keep a record of each repair or just do the job again with different solution.

frozen mosfet ? this mosfet is really a hero ! i don t understand what happen too , it happen sometimes to me too

Dear Sorin both mosfets of the image were P-channel, how is posible to be working if the gate of the second one had almost 19v? I'm starting to believe you have a deal with the god of electronics. Keep being like you are and Merry Christmas.🎄

this was grate video loved, is there anyway youcan do a good video about mosfets ???

My master., Maybe the mosfet is partially short must be change.

The lesson i learned from that asus laptop with the charging port is to always test with your own personal known working charger first.

The ghost gate signal :)

So Sorin . . .do you short the joined 4 pins to the gate or to the 3 joined pins ? Which is it !

Poate ar trebui masurata rezistenta intre G si S. Poate era scurtcircuitat G cu S si la conectarea lui G la masa s-a eliminat partial sau total scurtcircuitul. Poate e un condensator intre G si S care era scurtcircuitat si miscarea inteligenta cu conectarea lui G la masa a inlaturat scurtcircuitul :) Deci e buna metoda :)

Hi Sorin for swithing mosfet you need abouth 6v difference. On the p channel you need at least 6v less dan source and on channel n mosfet you need 6v more. So on channel n mosfet you will see about 25v on gate. Problem was a frozen mosfet this happens sometimes the 6v on the gate is normal. Regards Steve from Belgium.

The first MOSFET may have been affected by static charges at its gate, that may have remained in that gate keeping it off, maybe be it was due to stray ekectricstatuc charges generated

Bypass drain to source of the first mosfet and see if it behaves itself, Ooow im dodgy now he he :-D I hope you have a loverly xmas sorin :-D

A dodgy fault. I believe the 6 volts on the gate is indicating something that is weak. Whatever is giving the signal to the mosfet does not have enough power to pull the gate down. The fault might be in a chip? Or in the power supply to that chip?

Im sure sorine stopped the video and shorted that MOSFET 🤣🤣🤣

Sorrin, which must i checked. for the case of charging but 0 amp current . I've replaced the charging ic, high mosfet and lo mosfet. . and other checks, all seems normal . no difference . only batt voltage on battre conector

WoOoOoOoOoOoW real magic EleCtRoniCs

i wonder if the obviously missing ram slot could have any consequences to the pcb's circuit?

Extra for experts !

Hi Sorin. Why don't you ever repair desktop PC motherboards? I'd like to know how different they are from laptops and how to fix them. Thank you.

Don't you just HATE problems like that? It's fixed, but yet it's not fixed. Never heard of a mosfet getting 'stuck'. Will be interesting to see if it returns in the future, and if so will you be able to find the real issue?

Sir I’m seeing your work from time and help me to learn many things.sir I have samsung rv511 laptop in which processor is dead tried to search for processor but not getting it and very costly can you please help me

@Electronics repair school what would you do if a laptop shows a charge light but when you press the power button it won't come on removeing the ram cd drive hard disk wifi card but nothing remove the the power button and trigger it with a screw driver but nothing and the charge light shows even after removeing cmos battery it still doesn't turn on or even try to turn

Mosfet is a hero 😂😂

Hi there , What is meaning of, charging port plus ?? that means middle pin ?? thanx

It was the bios battery. It happens all the time in a dell xps. You take out the main battery it doesn't turn on. Take out the small bios battery put it back and it turns on. Bios fault.

Master Sorin infusing his dodgynes powers to the laptop, and than he starts working again 😂😇😂 thank you Master for the amazin content

P channel MOSFET gate voltage will be lower than source voltage either 0 or anything below 19 N channel MOSFET gate voltage will be higher than source voltage

I have a Asus aio ET2231i...The problem with that is a running browser or several browser open running and blinking back to start or back some minutes or seconds..if i are on youtube and looking at a video i can see without issues a minute in..and then the browser starts running for seconds,and skip back a couple seconds or skip to the start again..its a hell of a problem..i have shifted the harddisk with a ssd,sat in new windows 10,but no...same problem,and i have upgraded all the drivers..Can some of you explain what is wrong? i am out of ideas here...thanks in forehand!!

Because first mosfet refer to 19v. Even 16v enough working for it.

If there is no "magic smoke" then there is no magic, only happy little accidents

they didn't have the money for a bios battery, but it's ok we're cool! :DDD

If i remove the HDD and put that in the dvd place by caddy and put the SSD in the the HDD's place, Can the laptop's motherboard be damaged in the long run.?

👍👍👍

My pc turns on the charging batery led and the fan, the fan turn off after a few seconds, i found a block of capacitors with short and that block get hot when the pc is turn it on. What can i do? I want to remove capacitor but which?

Sir i have a question for you, imagine the upper MOSFET of 3VAlws has shorted. Then if we give 19 using dc power supply(without using charger) . 19 V will directly go to the 3alws section and components will burn? . So my question is is it correct that we supply 19 v using power supply without checking impedance for dead laptop?

Can anyone recommend a repair shop in the UK that does motherboard repair? Not just replace the whole motherboard? Not turning on at all.

💙

No CMOS battery, all its functions are delegated to the main one, hence the two screws through it. All these "Skullcandy" branded Toshibas have this buggy behavior. It's a "buy a new battery every 2 years" "feature." 🤣

The limit between alive or dead laptop is 6v, i cant stop laffing LOL