How to diagnose & repair a phone charging circuit - Samsung s10 dead, not charging repair

[@kenwamasho]

When you mention the temperature you are using to reboil and removing the chip that's a goldmine of information to newbies like me. Thanks a lot.

[@gizmorepairs]

All hot air stations are different, even the same model can vary. As a newbie you need to practice and get used to your own machine

[@stejereannicolae]

Nice Sorin that you make video whit phones , in mi workshop 90 procent of customers come whit phone , i just replace the motherboard , it cost little money becouse i buy broken phones to have for spearparts , buth if some customer whants to save data is good to learn and be abble to make this kind of fixis, buth i am learning , and dont have all the technology to make fixis like you do , buth mabe in future whit hard work we will have it , and is nice to be abble to learn from a profesional , is wery hard finding schools that teach you real fixing like you do . I whiss you all the best Sorin .

[@Vander-from-zaun]

Mr.sorin pls phones circuit explanation like the one with laptop motherboards you did some time ago it was gold to look and understand what is happening made everything so much easier

[@P.M.88]

i did this repair on a samsung a51 its a very common issue. top work

[@heno_3098]

I agree with the diagnostic procedure you showed. But one reservation about your procedure: I just never do the thing of disconnecting the battery from the phone while the OS is booting or running. You surely know why I am writing this. And I would like to add my experiences regarding phones diagnostics: The internal resistance of the cell (its lowest possible value) is of course very important so that the phone can transmit stably at full power during a call / data transfer in places far long away from the mobile network antenna (weak signal) and also so that the phone does not have problems with the stability of the CPU power supply etc. at full transmission power. Some mobile phones, with a battery that has a high internal resistance, behave in such a way that the battery status indicator drops sharply during transmitting, others have a problem with the transmitting power module, so simply the phone pretends to be on the network, but in fact is unavailable, and other models they just shut down out of nowhere when trying to transmitte. Your battery quality test was just for information, I use a simple internal resistance tester for this, consisting of a load resistor with a value 2 Ohms, which loads the cell with a current of about 2 Amps at voltage of cell 3,6-4,2V. Furthermore, a cheap multimeter permanently set to measure DC voltage up to 20V and a second cheap multimeter for current measurement and one button. Surely you know what I mean and how the internal resistance of a cell or battery can be measured in this way, provided that its open circuit voltage is at least 3.7V. But for others: You simply measure the no load voltage, push a button, so by button connect the load resistor through the ammeter, and measure the voltage and current. You divide the difference between the no-load voltage minus the voltage with the load by the measured current (Ohm's law in practice :). Furthermore, the electronics that the battery contains should protect the cell against discharge below 3V, but in your case the cell was discharged below 3V, which probably means that the phone was probably lying in the cold for a long time without charging, or the battery electronics do not have the mentioned type of protection or battery electronics have some leakage current itself. I don't need to explain what happens to a Li-Ion or Li-Pol cell if its voltage is below 3V for a long time, right? And one last thing, you should add a current measurement of at least from 1mA to your lab power supply. I mean that with a laboratory source that can display the lowest current of 10mA, it is not possible accuraccy to measure the current draw of the phone in stby mode or check whether the phone is not draining the battery even when it is switched off, which is quite common not only after damage to the electronics caused by liquid entering the phone, but also due to leakage current of various ceramic MLCCs and damage to the power management chip. I made the mentioned modification by adding a cheap multimeter set to measure voltage up to 200mV to my laboratory power supply and this multimeter is powered by an external power supply galvanically separated from the branches of the laboratory power supply and by a suitable voltage divider made from resistors and a potentiometer. I have achieved that this multimeter measures the voltage drop on the power resistor of the lab power supply, which is a part of it and serves to control the passing current at the output of lab power supply. I personally use a 0-30V 0-3.5A linear adjustable power supply that I made myself 35 years ago and uses the MAA723 IC (LM723CN). But of course, one of the shown USB testers could also be used to measure the current, provided that you modify it so that it is externally powered from 5V but measures the passing current as part of your adjustable source, and I think that modification is easy.

[@favioquiros]

Again and again, I really apreciate your videos.

[@RyanC7777]

I have found the solution for my phone that I've been struggling with. Thank you sir.

[@mohatechcyber8633]

MY BR0O YOUR MY BEST ELECTRONIC TEACHER SHUKRAN SANA NDUGU

[@oceaneight5583]

Whos says your Dodgie.... ??? Other dont understand Raw Skills and the kindness you have in your heart... Again you amazed the croud with High Skill you have.... Thnk you Sorin...

[@ronlevin2339]

It is so cool when you do not need to separate the boards like in new iPhones

[@kalmadolang3583]

your video is always my favorite to watch everytime you have it...wish someday i learn a lot like what you do sir..youre my idol...im from philippines

[@mikimehandziski1045]

Excellent teaching skills like always. 👍

[@MrRvdbeek]

Great great explanation to repair a faulty charging phone. Sorin thanks for sharing

[@Popeyes66]

Great fix Sorin & no dancing from you,yipee.

[@SONNYemc]

We need more of these jobs

[@bobme4951]

Sorin you skiped the clearing of the balls on the video (i know you did it) on the chips , we dont mind big videos , seeing you working with your awsome precision teach us a lot of details to make us better

[@mm0077]

Super, Open-hearted, Realistic, Intelligent and Nice = to?

[@audisam]

When you are removing the chip how come the hot air force is not pushing the rest of the smaller chips off their pads. Even when I'm lowering my blowing force to the minimum it still seems to move them. Great work Sorin.

[@macsouell]

quick question, what air flow, bezzel and temperature to use to remove the heat shields to see U8031 ? My hot air station is a quick 861DW

[@Swenser]

Maybe bridged pins on old chip. Would be good too see you put back old one to confirm. but I guess time is money.

[@georgeindestructible]

I guess it might make the swap of the chip even more reliable if we preheat the pads for a bit with the heat gun before we place the new chip on and the maybe then we can place the flux on the back of the chip instead (i mean we'll have to do this in the reverse order of course) then push it down and heat it with the heat gun again to finish it? I lack some parts and a device to try it out currently..

[@scroopynooperz9051]

God / Allah / Cthulhu / Buddha bless this man. He's making us all smarter every day.

[@teslasapple]

S is for Smooth… S is for Sorin 👌

[@OTHMAN_OV]

im learning from your videos, much love

[@merrylane2236]

Thanks for your videos Sorin. In one video, you mention that a linear power supply is better than a switch mode power supply for diagnostics. Is this becuase of the noisiness of the switch mode power supply, or for some other reason? Also, is 30V-3A enough?

[@bobme4951]

No its not for the noise is for the clicks you can hear on shorts , and try to find a 30v 5A power supply cause most laptops work up to 5A so you can have an edge on some repairs . (gaming laptops work around 10 A tho )

[@chizobaroland1739]

thanks sorin but we would like you do a video like phone diagnostic from beginner point of view

[@ignaciosuarez9732]

it ended up being borderline too much work to be worth the repair, but it was instructive so we have that going for us, which is nice

[@paulmendota]

its for learning more than anything.

[@ignaciosuarez9732]

@@paulmendota yep he's a star

[@netrosolutions]

Thanks sorin

[@mrbot8062]

Finally foubd out the problem with my S10

[@bikhlarrovamarakov5392]

for me rebulling is a must done :) and heater near cpu or memory is terrifying lol ..i love u'r confidence geart video

[@amabraghanemimiegha221]

Thank you so very much, Sorin. You're superb.

[@ianhamilton8981]

Thanks

[@mgomez5606]

Looks easy when you see someone that knows what they are doing.

[@joliettt]

Amazing once again.

[@ivanzsar]

sorin is our master.. but for us, don’t skip proper reballing.. oke? and ooh.. we don’t touch the chip on the top to see if it’s in place.. do it on the sides.. oke?

[@bobme4951]

Sorin what is the diference between your normal usb meter and the other meter that shows diferent (higher) values ??

[@gizmosfix]

It is a common issue of no power no charging on these Samsung Galaxy phones from S7 to S10. Galaxy S20 and up are very hard to repair due to the sandwiched motherboard.

[@gistapolo4918]

thanks good job

[@mustaphahammad1196]

That was a nice one sir 😊

[@Pihmusik-PiCh-Expert]

[@prabuddhadas6441]

which schemetic you are useing ?

[@norbert1439]

thanks for the nice Video

[@maklogetrich2378]

Samsung AFC 9V @1.67A (15W)

[@omi20]

How did you know it was that particular chip?

[@jamalfastpay3482]

sorin why you do not explain schematic how you figured out this chip faulty?

[@electronicsrepairschool]

I did! The only chip which is getting the voltage from the charging port, is the charging ic chip, i showed in the video how to check

[@blue-flame170]

Hello I have a Samsung A15 mobile that charges with 380ma, and with the same charger and connector, another mobile that charges with 1800ma. What is the reason for the slow charging in the first mobile? How to solve the problem and how much does it cost??

[@segunoniyide9787]

How can i get in touch with you

[@kingnkwanyana2326]

Hi everyone. I have a samsung a21s and the ldo voltages are not present when the battery/power supply is connected. It is available as soon as i plug in the charger and the power voltages are not present. What might be the problem? i am suspecting both the pmic and charge ic

[@oilybrakes]

This chip is kinda a typical defect on Samsung phones.

[@ronlevin2339]

usually result in 0 current, not low current

[@habiboumamaneousmane]

Please the name of the small power supply

[@bull.dog.]

👏👏👏👏

[@dagi_tech_graphics]

How to find any IC on phone PCB?

[@weerobot]

Cool...

[@NicksStuff]

So this is a £60 job? Do you still charge for your time if you can't fix it?

[@promanamigo3221]

I wish kiss your mind

[@marianbratu2946]

😚

[@Issam_Gamer2]

Guy's why this video is unavailable??

[@kam_mil]

Is the battery not going to explode from all of that current?

[@johndopedo3298]

What do you mean by "all that current"? Lithium batteries can be charged at it's rated capacity, which in this case, if the battery is 4.1 amp hours, can safely be charged at 4.1 Amps, maybe a little more. If he sets the limit to 5 amps on the power supply, the battery will most likely not take more than 4.1Amps when charging.

[@kam_mil]

@@johndopedo3298 Yes they totally can, I own a 67w charging phone myself, i'm talking about pushing the current into a dead battery, below its safe voltage.

[@heno_3098]

No, because it wasn't too long and Sorin has an estimate in his eye as "prepared calibrated fuse wire on many years ago" :-D

[@stejereannicolae]

you sad that the broken motherboard is not the same as the phone buth for me both look 10 plus xd

[@therealspixycat]

Sorry but you don't loose any current: you only loose voltage over the leadwires

[@electronicsrepairschool]

You promise you will come back to this post and you will apologise and thank me when you will learn you never loose voltage on a circuit, you always loose current only and the voltage drop is because you are loosing current? :D

[@asv5769]

First Kirchhof law states no current is lost and second states that no voltage is lost. Maybe it is wrong terminology

[@nilomyki]

I keep getting unsubbed to the channel.