like MOSFETs, Zener diod is almost certainly part of the charging chip design template. Most of the manufacturers implement reference design instead of inventing their own weel. The problem with input voltage protection is that both MOSFETs could be shorted by voltage spike of a malfunctioning power supply. If it builds up a high-frequency AC ripple, it may be overseen by ACDET regulator but it will still blow insulator in MOSFET. in this case, you have uncontrolled DCIN going directly into the main power rail which is always a bad situation. Zener diodes are used on every single HDD as an over-voltage protection fuse - it gets blown very fast and it shorts power rail to the ground. Think of Zener diodes as an over-Voltage fuse. Since you did not replace the Zener and customer will use the same PSU, this laptop might come back at some point and I guess if it will, it will come with a blown cap or VCORE MosFET.

Really honest person,trying to explain what’s going on , after finding already problems. Thankful

The best teacher I have ever seen.

It's not zenner diode, it's reverse polarity protection. See it's pd9, not pz9 and the symbol shows a diode. That's why it is there for reason and not stupid.

Not stupid if they want the laptop to "break" easily...

@rezakawaii2836

Жыл бұрын

Now that's not the answer were looking for

You chose the HP because the color matched your shirt. Thanks for today's lesson.

@servicestv-paraboles-pcs6504

5 жыл бұрын

i said the same think before reading your comment i swear hhhhhhhh

@Frank-Thoresen

5 жыл бұрын

That made me laugh. I had to blink twice 🤣

@brk932

4 жыл бұрын

Weirdly enough it's how people buy HP's

@tanvirahmedsiddiquee127

3 жыл бұрын

Bloody cheap.

Happy return teacher, your classes are greatly missed; thanks for the experience and tips, greetings from South America.

In my PSU designs I use suppressor diodes to protect from spikes, when they fail, fail short and burn out the fuse, so the rest of the board is safe and doesn't stress the charger or whatewer the power source. HP really should put some kind of fuse to the power rails. EDIT: if something goes wrong with the charger or wrong charger plugged in tantalium capacitors blow up pretty agressively. My guess they use max 25V components.

I like your way in analyzing and solving each case you come up to, i am addicted to your videos, a week without them OMG

"Now I'm angry" ..the way you said it... Loved it! Very educative as well.

I love all your videos.. I truly admire your generosity in sharing your valuable experience and knowledge. Bless you!

Great stuff. I have just bingewatched about 4 hours back-to-back. Thanks.

That part you were pointing out is actually a TVS diode (transient voltage suppressor) marked as "IV". You can look at it's specifications under it's equivalent being SMAJ20A tvs diode. It was a bit tricky finding it as either new semiconductor devices do not have a standardized marking code or, that (somewhat imperialistic) companies have their own marking code which at times do not even correspond to their own data books.

@Drottninggatan2017

Жыл бұрын

Now if these diodes are shorting to ground on over voltage then why would it not work correctly again when the over voltage is gone? I suppose that this diode was damaged. Permanently shorting to ground.

HP designer and his manager disliked the video!

@EddieLeal

4 жыл бұрын

The truth hurts. Sometimes when the baby is ugly you have to call it ugly. You cant fix what you don;t know, or accept in this case, is a broke system. FIX IT HP! ;) lol!

Long time no see Master. I've missed you.

amazing talent you have sir.....I do repair things, but a laptop on this level is something I always wished....

Thank you for being such a good teacher!

Subbed and Thumbs up! Thank you so much for this! I was a repair engineer _Once_ and I still like to think that I can tackle most things but I was presented one of these in a very similar scenario, with the exception that the charging light comes on and it will charge the battery but when the power button is pressed, lights (but no screen) come on briefly; fan spins briefly then everything goes quiet, leaving only the charge light on. PSU is fine but *not* original. One of my excuses to not attempt something like this is that I don't have a Scope or re-ball facilities but you prove the contrary, using tried and tested basic equipment to repair things that would otherwise be 'beyond economical repair' by smaller companies and astronomically high priced repairs from manufacturers.

@ajaytherockboy7940

3 жыл бұрын

Did you fix it sir?? I have the same problem

Wonderful, I love your videos man, so much to learn from, thanks a million.

I have repaired my HP Pavilion 15-n225sf , i can't believe this, you are... a master, and i'm as far to be skiled as you are, Thanks thousand times.

Loved this one. thx so much for teaching me

25:46 where fun part starts :)

@OliviaIsTyping

3 жыл бұрын

This stupid I swear I get angry

That stupid zenner diode allows you to have a client =) your videos are fantastic, thanks for sharing your knowledge!!!

Did the guy with the computer give you the shirt too?😂😂 Love your stuff man.

Your all videos are full of information Thank you sir Love you

Excellent work!! Love your lessons.

wow... you really cant understand how much you've been a source of inspiration to me. thanks Sir... i really appreciate this

keep sharing sir ..this a big help to all beginner like me ..to become someday like you sir

Hope you had a nice holiday Sorin, I was wondering where you was, I missed your videos big man 👍🏻

Always love your teachings Sir..thanks you come back...yes i believe hp got a problem as i experienced

Thank you Sír you are a great human being for share all of this. I wish I have the 5 dólares to joining your school.

Welcome back ,nice to see you again.

Love the way you teach troubleshooting.

Welcome back Sorin we miss you Thank you for the nice video

Am grateful for your videos it teaches me new methods

A very very good explanation, you're the man Sorin !

This is a nice one, thanks for nice diagnosis. I am being inspired.

He kinda looks like a grandpa teaching his grandchild with so much care and devotion. 💓💓💓

'This is moral thing' Well explained. Thanks Sorin

happy to see you Sorin :) we missed you

Very good your point of view HP notebooks, Excellent contribution to knowledge

Thank you Sorin, I imagined the fault before you show it just because I saw your other videos before ... You're a master in the Power fault !!!

Great video.I agree with your reasoning on the protection diode,which does not really protect but kills your laptop.

Thank you so much for today lesson!

Good job Mr. i m learning a lot

Wonderful, I like your enthusiasm

You are the BEST Sir, it was same on my laptop, GREAT...!!! HP ab203TU ... I solved it looking your lesson.. Thanks again..

Hello thanks for sharing your experience. After you remove the zenner diode you had to put a bridge wire at it place right?

Sorin, they got you back just to fix all the unfixable ones. Admit it!

I fall asleep from your calm explanation that I cannot follow it, you are the master of electronics

i have a limited electronic education but you explain so good i can understand .

very helpful to our friends ,, all of you are very kind

nice work sir I learn something in this video

31:05 haha what is that someone put coin in USB port ? :O will that make laptop dead ? Respect! i learned so much from you and every day learning working with laptops 20 years and still every day I learn something new from you ! God bless you!

Thank you sir! I learned a lot from you.

started more liking for your lessons and a style of teaching too. very informative. Thanks

felicidades maestro y gracias por la leccion. see you next one thanks

i missed you man, the guy from South Africa.

Hi Sorin what if I dont have linear power supply and i inject maybe 5v 2a through the pwr resistor can I find short with this method or I need higher voltage?

Thanks for the great video. I removed the zener diode but still the PC wont start and no power led lighs up. Voltage over the zener diode when removed is 19,9 volts when you had 0,5 volts..so obviously there is another problem right?

Great work Sorin, thank you

You are the best man love your'e video's I learn so much from you thanks man

Welcome back! Wanted to ask, can you show how to diagnose if a hub is dead? Thank you!

Helpful video 👍

It may be a Transil diode called also TVS (Transient Voltage Supressor). It is used to protect against overvoltage. It shorted itself but protected rest of the components. In some cases transil can even protect against catching fire or explosion of Lithium-ion batteries.

@paulf1071

5 жыл бұрын

Yes, it may have been a TVS diode doing its protection job correctly. That TVS may have been under-rated, or else a massive voltage spike appeared on the line.

@NeuronalAxon

4 жыл бұрын

Thinking maybe the PSU failed and sent a voltage surge to the laptop?

wow, best ever video on repairs you are truly a genuis🎉

I so much love the way you teach... I wish I could be your student.

@NeuronalAxon

4 жыл бұрын

You kind of already are if you're watching his videos. ;)

@okolojohn9866

3 жыл бұрын

Can I have your number

God bless you for today’s lesson ❤️🙌🏽

very cool technician you are ,following since TOGO

I should call you "Master"! It really helped me a lot. thx!

If the Zener diode wasn't there you would have a much larger repair job. Yea the Zener killed the laptop but it prevented damage elsewhere. The zener diode is probably there to meet some safety agency requirement.

@gabiold

5 жыл бұрын

There are supressors or MOVs which are designed especially for surge protection. Zener diodes are not really suitable for the task. Not in this power range. On a low power rail maybe, or on an I/O line, it is.

@Oak690

5 жыл бұрын

@@matrofixWhat did I say that was disrespectful? Just stating what I felt was a reason for the diode to be there.

Amazingly intelligent man I wish i was half as smart as you Sorin. Your videos brighten up my day!

capo total la manera de explicar es sensacional soy de argentina y entiendo mas con vos que con los de mi propios idiomas

very clear sir! and thank you for the lesson yeah!

I have this exact laptop and for some reason it wont switch over to battery when you pull the AC. Its driving me insane. it also takes forever to start up when battery installed but remove battery and everything is good. Replaced the battery and the problem remains. please can you advise what it could be?

thank you for New video sir.. Miss you

Sorin, your shirt matches the laptop!

now I am going to look for zener fusible diodes right beside a capacitor....ACER ASPIRE 5333 water came out from ceiling it got poured and now hard to think more possible solutions. Thank you for sharing another idea!

I have a acer aspire that dont power and with thermal camera i see that the diode is only thing getting really hot. Should i just remove it or have to short both ends ?

you inspire me and i think your job is pretty cool i have a similar problem but the super I/O (ITE chip) is getting hot and i dont have a voltage measure device

you have to come together with Louis Rossman :)

happy to see you again !

can i ask, what temperature you used for hot air blower? thank you

Thanks for the video. I have a HP Pavilion and it has the same non charging fault. I have done all the things suggested by trying to run it with the battery removed and trying to discharge the circuits but to no avail. And as you have done, I checked the power supply to give 19V. I would never have figured out how to take it apart if not for your video! I've found all the screws and have almost prised the keyboard off but my version of the Pavilion has a DVD drive and there appears to be a screw hidden by the drive. I might have to take the DVD drive out to get at it but I can not see how to do that. At 5:58 you just slide out the module that is where my DVD drive is, but yours doesn't look like a DVD drive. Any suggestions? Cheers. Edit. Just seen that you undo a screw after taking the module out. That is the screw I can not get at.

@TCSC47

3 жыл бұрын

Just found a utube showing how to do it! Hooray! It was just a matter of pulling the drive out after removing the single screw holding it. Cheers again for the help!

Learning a lot from you . Thank You

I have the same motherboard and I removed the zener diode as I had the same symptoms, I now think I also have a blown mosfet M3016D the big mosfet in this video below the zenor diode with 3 legs, is it safe to bridge this mosfet or would it be safer to get a replacement M3016D mosfet, thanks, P.S love the videos I am learning more each day

Have this HP Pavilion g-series laptop that when you power it on the caps lock flashes and the number lock flashes but no post into the bios even nothing just hear stuff booting and black screen,I've tried a second screen nothing there either,any suggestions Sir?,tim. (Need Your Help!)

what was that thingy you took out from usb port ??? 31:08 ???

Thank you for the lessons

Thanks so much for this nice and clear video!!! I would like to have your thoughts about a laptop HP envy i7 17" I have which does not charge the battery when it's ON and charge it when power is OFF. power supply has the light, when the battery is charge everything works. I tried to remove the battery and power ON but apparently this laptop needs a battery to power ON. thanks for your answer.

It’s a great repair again And indeed the blue case is matching

buna, frumos dom profesor, apreciez munca depusa.

Awesome channel. Godbless you sir.

thanks mr sorin,you're my teacher. i get a lot money from your videos

I Recived this laptop on my shop same day this video was Published, and you know what? Same problem, i think i owe at least a Coffee to Sorin! :D THanks!

@NeuronalAxon

4 жыл бұрын

lol, no way!

Excellent, compulsive viewing ! The TV is dead !!! Great entertaining show !!

You are amazing man Thanks for o lot of hints and I recovered a HP Laptop coz of you.

you are simple to follow keep up the good work

Sorin I wanna know something. Now whoever is sending you those laptops to you for reapirs, ( you said its from another shop) are those people or that guy not watching your videos and learning to troubleshoot? Get my point? By the way thanks so much once again. Love. Good luck. 😊 You are a man of 'heart'.

halo, a got a Sharp tv screen LC-40LE185M and the Menu does not show all the items (the Menu appear vertically at the RHS), two items that not shown are USB and RETURN. it looks like the menu is drop downwards causing the last two items to be invisiable. in fact when i switch it ON, it only shows half of the name Sharp (logo) at the bottom of the screen when it start up. iam trying to fix this but i dont know which board to test...any advice? thanks, i am new here in yr ch