Class... Is time for a knowledge test :) Part 2

[@Radek__]

25:13. Sorin, you have right but not all. The DATA wires are used to DETECT what did you connect to Smartphone or tablet (The charger or the computer/laptop) This is a protection for usb 1.0 and 2.0 ports. As you know the usb 2.0 from computer can deliver only 0.5amps maximum current. If something will try to draw more current - then computer will shut-down the usb power line or trun itself off or restart. So IF you.... connect a charging cable into computer USB port, then the battery will be charged only by 0.5 amps. There is no way to achieved more current in this way. The charging IC will be limiting the current to 0.5amps. But IF you connect that cable into the charger, then charging IC will detect it trough data pins and then release the limit and start to charge battery with maximum current. So Smartfone or tablet is NOT using data pins to draw more current trough them but ONLY for detection. The question is - how the charging IC is detecting the charger or the computer usb port? Very simple by Low or High state. If you short together data pins (data+ with data-) ten you force low state and the charging IC will detect it as the charger and it will increase charging current. If you have open (not shorted) data pins, then it will detect it as computer/laptop USB port. Some chargers of different smartphones are using resistor between data lines - but it is not necessary - for most of the cases (samsung, etc.) -the can be shorted together. So inside of the charger - data pins are shorted together or there is a small resistor between them. This allows you to use the same cable for fast charging or to transfer data to computer. Do some tests, you will see what I mean. .. and about that case on video - if you will be have any the situation like this in the future, then you should check the charging port - for cold solder joints on data pins or to check if they are not bent together- it could give the same symptoms like one cable is charging good, second bad. You cut the data wires in that cable on the video while it was connected to your smartphone -and the charging current drops down to 0.5amps only. You could short data wires together (on the smarphone side) and then see that currect will comeback to high value. (because this cheating the IC to think that orginal charger is connected)

[@kahlid-ataya]

you are a great teacher your knowledge and experience and logical explanation is awesome for the first time in my life i such information they are very useful for me and my work in electronics field

[@TechbayElectronicsRepair]

Hi all greetings from Kenya, I have learnt so much watching you fix stuff using power supply.

[@breakthru3000]

Nice lesson, thank you. Some batteryes had a built in protection circuit. If the battery droped to, let's say, 2.5 volts, you had no chance recharging it with your method because the protection circuit would not let you. The only chance to revive such a battery is to disasemble it (plastic part covering the protection circuit) and put some voltage directly on the battery.

[@Sang123-19]

I like all your videos... I saw so many youtuber but your teaching method is super and you have great knowledge sir... Am always greatfull to you and you are valuable person for every one.... I have no words more you are really amazing

[@marcobohorquez4711]

Good lesson. Every time i watched one of your videos I learn something new!! Thanks.

[@juanchizabaleta2405]

His class is very clear, thanks and greetings from his disciple from Argentina.

[@CyReVolt]

Some devices charge fine without data lines, like that tablet, some only take low current then, like the phone. That really just depends on the charging circuit. :)

[@doctorbadass4782]

Thanks Sorin, I really like this style of video.

[@Kris0725PL]

I bought 3 broken tablets for repair because like watching your videos. First manta tablet stuck on android logo...repaired 100% by upload new firmware. Second manta tablet zero reaction on power button...not charging...repaired by change diode zenera...workimg but lcd is broken. Third tablet colorovo vision 7i(intel inside) working but lcd is broken.

[@simeonmihaylov6123]

I am happy with my guess ^_^. All I can say is, what I know is thanks to you. Before watching your videos - I would have never guessed. Thanks master.

[@lynspyre]

Data lines are used by modern devices to enable fast charge mode on the charger.

[@morto360]

I may be wrong but i remember reading somewhere that devices do charge without data lines but on slowest // safe speed. If you wanna fast charge, data is required.

[@incandescentwithrage]

Yes, on a fast charger supported by the tablet, it will increase the voltage above the usual 5v USB. Negotiated using the data pins.

[@ΣπυροςΓιαννας]

I think you can buy cables without datalines and have them only for charging. So the new phones and tablets probably are made to work without datalines but slower

[@paulodagraca3469]

Yesterday, i wrote.. Let me use 2 of your quotes: 1) "Let's come with the power supply, yeah" 》this was at 7:50 2) "We need some amp's" 》 this was at 10:40 The battery has got too low, you can verry slow charge the battery by USB 》this was at 7:10 Seems we are starting to know you really good, better than the batteries. Again greetings from The Netherlands -- Fan --

[@rayofcreation3996]

Paulo da Graca 😆😆😆 lovely!

[@kblectronix]

The component at fault was the ic in the battery. It just needed a bit of a zap to get it going again. How many devices has anyone seen needed that, all of them? :) Usually the charger cable works but leave it overnight. More interesting was Soren's results on the charger cables. They do not have to carry data as far as I know, just power. The cables he was testing might of been a duff batch, and being as he's not the boss, not tested very well. :)

[@intrax2tv]

Can't believe I was right, low battery ! Data lines not used on this tablet... RTFM

[@iTCXtreme]

AFTER LONG DISCHARGE BATTERY GOES INTO SLEEP MODE. THE BATTERY REQUIRES A BOOST CHARGE TO BRING IT BACK TO LIFE. YOU CAN USE A BENCH POWER SUPPLY TO BRING THE BATTERY BACK TO LIFE. SET THE BENCH POWER SUPPLY TO THE BATTERY INPUT VOLTAGES/AMP.

[@rayofcreation3996]

iTCXtreme thank you for the imp info. Sorin to keeps talking about this often and has demonstrated it to us too. Good luck.

[@AlphaRobloxer]

Extreme thin wires and low quality wires can cause low charging current.

[@09danstart]

I knew the battery was too low for it to charge, I use very short cables to charge phone or tablet for better current on my homemade power supply, just a pc atx power supply with a few usb ports added and I shorted the data pins on my power supply. But the original cable supplied with phone or tablet is better.

[@scruffyget]

Thank you for all your video's ,and your knowledge.

[@allexandruprroca6713]

the cut out voltage for a li-ion batery is 3v , sure the charge i.c wasn-t chatging it , cuz the i.c from protection board of batery cuted the continuity because it saw the voltage under 3v , and just when you kick charged it , it reactivated the mosfets on protection board of batery , simple as good morning

[@kytkinlevy]

Thank you for very interesting test. In my mind I was wrong but now I know! Peace out my friend,

[@aymannabil3810]

Sorin, thanks for all your helpfull videos..you are a Good teacher...i wrote the right answer in previous video; because of u

[@TikusCZ]

Some devices sense dedicated charger by shorted datapins or expected resistance between them. Some need different voltage on each datapin. It all depends on vendor implementation as there is no common standard for this, so it might vary on each vendor.

[@angeloaemmeart3620]

incredible, no data line ... this is a very good video (like the others). thanks Sorin

[@bilalsoltan8688]

with phone is different because probably it has a fast charging technologies with use a data lines thank's

[@yansper]

How to detemine that any IC like RAM, Processor are shorted?

[@elektar121]

maybe the cut cable has shorted data pins in the tablet side plug...?

[@Chupacabras222]

If you wouldn't fix it, and just let it plugged to charger for a day, would it recover the battery? I mean 90mA would eventually bring the battery above 3V and start the charging with full current.

[@wynout]

So funny, I am wearing the exact same short pants because of the hot weather :D Initially I thought the voltage was too low to start a charging process (constant current and then constant voltage).

[@QsTechService1]

I have been running into this issue with the amp charging with different devices you have to use all different cables. Crazy crazy 😜

[@prembouncer1]

With many android phones and tablets the device charges fine without data lines

[@jment34]

Interesting I didn't know there was so much difference in cable quality. I know it's possible to measure the amps with a multimeter but it's necessary to cut the cable. Is it being measured by the power supply?

[@panaitepaul6798]

I'm sure if it was left connected to charger enough time, overnight for example, even with 0.09A would have come back alone. I got this with a tablet samsung galaxy tab ... (I do not remember) 10 inches.

[@MindYourBusiness1970]

Nice ☆☆☆☆☆ I had the point but I was too lazy to write about the tablet forgotten in the drawer

[@keithking1985]

I just watched the 2 videos!! and loved them.. but that tablet will be back in to you again(if it hasn't already) My nephews kindle has the same problem. what I mean is the tablets charge protection is allowing the voltage to drop below 3.2V on the battery.. and it happens when he lets it run completely dead passed zero percent. I tell him put it on charge before that. but when it dose let it happen I had to keep putting the charger in and out and in and out like that for ages until the voltage creeped up.. but here's a good one for a laugh'',.. those doller store pound shop power banks would work a treat to bring the battery up(better then what I was doing) my thinking was that it has a battery protection circuit already in side it and might help to stand in for the faulty one in the tablet.. now I could be totally wrong as I am still new to this stuff but this is what works for the situation handed to me.. so Sorin could you let me know if my thinking was right or wrong.. it would give me great pleasure if im on the right track coz I would know im learning.. but would also take pleasure to given the right answer and to put on the right track. (sorry or the long message)

[@IsaacOLEG]

or it only works with the battery temperature sensor on the tablet ?

[@abou-aicha]

مشكور على المعلومات القيمة و المهمة

[@gkasgtps675]

So i pass the class!. Master the old pnones and tablets charge with no data lines on,the use it only for data transfer.

[@pauldiaz4273]

gkas gtps congrats you on your way to becoming an aprentice for sorin 👍🏽

[@Tomtech29]

We do meet a number of surprises in this field ,came to me: Galaxy XCover 4 with a broken LCD screen the exchange seemed trivially simple:D but the phone has strange damage after starting there is a picture and then it gets dark,the touch screen "digitizer" does not react,there is also biping every moment. What do you think about this?

[@waynetaylor2784]

Yup I got it right battery just needed a kick start...

[@paulzac5481]

Yes thats how i explain it to the customers rather than change the battery and add more to landfill waste.

[@paulzac5481]

Yes thats how i explain it to the customers rather than change the battery and add more landfill waste.

[@salawalas]

Could be act weird, if you have a break on data lines in charging port or even further on motherboard, or is a malfunctioning charging ic. This tablet in Quick Charge 2.0 should take 1-2 amps on charge on discharged battery. Try to use genuine samsung cable to verify.

[@zyxnull]

- How many volts and amps did you applied to get it started? - Does your PSU has an USB charging port? - How the data lines help with charging? how does the charger "knows" when to use them?

[@wendelljackson1488]

I have seen you use your power supply (only a positive and negative, no data lines) to charge a battery in a phone. How can that work if data lines are necessary for charging?

[@kamil9216]

Data lines are necessary for better charging like around 1A and more and for transfer data. If data lines are broken, they still will be charging but with 0,3-0,5A because they not communicate with charger.

[@Inertia888]

maany chargers are sold that have only +5 & GND no D+ D- usually this is for very cheap cell phones ...is this where the difference is?

[@qwertzuiop7741]

Well, my Lenovo phone does charge, it even does quick charge without working data pins. OTG and PC connection does not work, but it still charges 12V/1.9A with original quick charger. Granted, I do not know where is the data connection broken. It may be the connector, or something else. I did not bothered to actually check it.

[@khalkhal2372]

Interesting lesson

[@DimitriPappas]

It's normal for a phone or tablet (Apple devices being the exception) to charge at 500mA with just the red+black (+,-) wires and no data (D+, D-) so that was expected behaviour :)

[@alienencounters5710]

thanks master sorin

[@AlphaRobloxer]

Great to see i was right with the to low battery :D

[@mohamadasriabdulazid4784]

I have seen this problem before, it happen because the voltage is to low to fully open a MOSFET gate, it only allow small amount of current to flow to the battery. This problem solve by apply extra voltage directly to the battery, witch allow the gate of the MOSFET to fully open. But when the tablet trying to start the screen it draw to much current and again bring down the battery voltage and cause the MOSFET to closing the gate. The way to remedy the problem is to remove the MOSFET and bridging the source to the drain, witch allow charging ic to charge the battery directly. it is recommended to use low dropout diod and fius between charging ic to the battery. To protect charging ic to be damage if the main power rail is shorted to ground or reverse current.

[@sergelavallee913]

Lol what are you talking about? You think the engineer did not think of that lol?

[@mohamadasriabdulazid4784]

@@sergelavallee913 nope because they keep using the same circuit from the first tablet. I never find this circuit in any other mobile devices accept laptop. Plus they use 3 MOSFET inside that circuit, 2 for charging and 1 for general power across the board. That is to much and overkill. And create this dumb problem at the first place. This problem will become worse when the battery has an internal leakage between positive to nagetive. It cause charging loop problem on other device and not charging at all in this freaking tablet.

[@andyturner1727]

Thank you Sorin , Great as usual : - )

[@fraizfester8713]

The more you live, the more you learn! :D

[@josuevillasante2546]

Thats was my answer. Charge the battery directly

[@machine85]

The data lines are used for data transmission and identifying the official Samsung charger. If you’re using desktop psu I won’t identify it self, this is more of protection in mobile phones rather then tablet.

[@akramnazeir5505]

thx sir too much 😍

[@Praveen_th]

Nice video!

[@bilalsoltan8688]

There is no relation between data lines ( D+ and D-) and charging lines(+ and -), the data lines are just to transfer information between the tablet or the phone and the other devices such as a pc

[@deft3562]

What about the charger connector on the tablet? I dont know, can it be broken? 😄

[@sergelavallee913]

That's what i thought at first but: What tells you that after the full charge the batterie will KEEP THE CHARGE? What tells you that batterie is GOOD? So, other tests to make after charging that batterie. Are de data pins good or defect also? What about the charging port on the tablet? Is it good or not? Soldering, good or not also? I think they might be a problem with the charging circuit here, maybe. Thank you. Keep up the good work Sorin!

[@electronicsrepairschool]

kzbin.info/www/bejne/nGOki5Johp5ofdE check the power supply, 2.14A - 3.7V that telling me everything about the battery, like, the battery its like new or a very low internal resistance. I did few videos about checking a battery life based on quick test with a power supply, check them.

[@sergelavallee913]

@@electronicsrepairschool Ok! Thank you Sorin for answering me. Very kind of you>

[@davidhiebsch9802]

thanks!

[@GregM]

Non working charging cables meet Mr side cutter pliers snip .. problem fixed with that cable and going down rabbit holes

[@COMPUTERREPAIRSCHOOL]

We love you

[@Hadadoh]

I think older devices without quick charge feature may not require the data lines for charging to occur.

[@astroman5923]

Data line use for charging is outdated it's bad design on board charge ic or or built in multimeter on the battery pcb can handle everything only use for data lines is for transfer and back up of data it's just poor design to use them for anything else unless your trying to squeeze money out of the end user to buy official cable and charger.

[@attainteddragon]

@@astroman5923 your not familiar with how usb-c works then. it can have different outputs based on (data communication) :P

[@astroman5923]

@@attainteddragon oh I do I'm saying the control circuit can be entirely contained on the pcb of the battery, or the charging circuit no need to control current on data lines leading back to the charger it's a weak design.

[@astroman5923]

@@attainteddragon The battery/charge circuit can easily determine saturation and drop current when desired voltage is achieved no need for data lines.

[@attainteddragon]

@@astroman5923 yeah, there are simple ways to do current sensing, but if there is little room or more importantly from a manufacturers point of view, it has to be cheaper. unfortunately we are stuck at this point.

[@PHONE-LAPTOP-REPAIR]

i think i almost got my answer correct.....nway thanks sir for the explanation

[@yvesrochet3288]

I am surprised that you use the words » low resistance » and « high resistance » in the opposite manner as usual ? For me, low resistance is near 0 Ohm, for you, it seems contrary.? What ? Tks for your very interesting emissions.

[@onetimelifebigcamera1607]

Ya I'm raight 👍

[@fufanaaahmadmohammad1291]

Thanks you prf

[@kayamkhorasi9395]

hi sir i have the problem in iphone x, its stock on apple logo,when i remove ear speaker flex its started hoe to slove that problem whithout losing face id can you help me out sir

[@sufianag5790]

i have problem with my xperia z5 can u help me fixing it ???? i've watched almost all of your videos and i got improved but my sony still big problem for me ... it was having problem with battery means 100% then becomes 10% then dies .. until the last time i couldn't wake him up by any charger with no sign of live .. i bought a new battery i charged it on power supply till it was 3.8 and the phone has no sign 😔😔

[@XLR8RRICK]

I can see the screen connector is not plugged in straight

[@defragment418]

Finally we have a working cable.... so lets destroy it for scienece !!!

[@computersrepaircotesaint-l7407]

always best tech

[@johnf3278]

Hi Sorin, love just killing time watching your videos and listening to you. And perhaps learn something. Inspired i thought i would replace lcd on samsung a300 phone. Got a cheep one (£20 ebay) but i cant get it to fit it's too thick. They say it's the cable not sitting right. But i cat see that. So asking you or anybody. Have had same problem. Think i am missing something? Thanks for all the stuff you do.

[@weerobot]

Cool...learning slowly......Tech can be weird..lol

[@bellslinki]

Dodgy cables! 😃

[@abdelssami]

Diodes gone wild

[@drobino]

Oooh i was wrong. I was thinking the battery is too easy answer.😃

[@sunnybabs9395]

Please can someone help me out have downloaded board view for motherboard but i dont see where i can download a file to view the board that am working on like Hp pavilion dv4 and the other board for free

[@margyjr]

Nice shorts Sorin, do you sell them in your shop, ;)))))))

[@lesleymunro4964]

Some devices will charge regardless of the data line status - I think apple were the first to start the Data line detection genuine charger crap. It could be that this tablet was designed/built before all this charger crap. My old THL phone is like that, it'll charge at 500mA regardless of what it's connected to. Also many chips will slow charge usually when the battery is under 3.0V - it seems to be the common threshold for lithium ion batteries to start faster charging. Below that they can gas and puff up. I was nervous watchng you jack 2A into the dead battery :-) I know you probably do it every day, and it's fast, but i'd probably choose something more pedestrian like 250mA, and give it a bit of time.

[@GPSOMG-]

Like the shorts :)

[@darrenstrathdee7425]

Tbh i see this issue more often in android devices. Not so much ios.

[@astroman5923]

Was correct then.

[@dormankenneth]

Like jump starting a car!

[@paulzac5481]

Yes thats how i describe it to customers. You dont necessary need to change the battery. Lets try this first boost the battery if its still the same then we change it yea

[@rtype4930]

finally what happened ? Was it a battery problem ... ? or something else ?

[@zx8401ztv]

So you tested us and the tablet tested you ha ha :-D I do not repair phones or tablets, so my method takes a bit longer.

[@mahlapropyzm9180]

You didn't test if the tablet would boot up once charged/charging.

[@emonhasan4032]

My Nokia phone doesn't charge with 2 wire in micro usb port but my Huawei phone does

[@arifryo6823]

Mr rosin..can you give tutorial for installing ic pmu , the basic. I try but always fail. I dont know if the connection that doesnt fit or the ic is already broken. The ic is always moving , is.it too much flux i use? I use it like flood

[@shoaibsiddiqui9188]

hurray i was right.....

[@Cyber_Tech_]

3.1 magic # lol

[@ziggy_makes_videos]

Hahaha...ur so funny boss

[@muruganh6202]

good evening sir from india

[@XLR8RRICK]

Who got it right?

[@mahlapropyzm9180]

You should keep those shitty cables, chop off the connectors and use them for the wire. You are always looking for wire...

[@zakhelemadonsela4966]

LMAO

[@benvarela134]

No, Soren, I don't believe it is just a low battery; there must be something else wrong with this tablet if you say the battery is good. Why not try a new battery, please.

[@kayamkhorasi9395]

hi sir i have the problem in iphone x, its stock on apple logo,when i remove ear speaker flex its started hoe to slove that problem whithout losing face id can you help me out sir