You're something special - i watched so many videos trying to understand how this chip is working- yours was the only one that broke it to details and explained the whole process, from A to Z- thank you so much for you time to make this video and hope you can make other videos explaining what to do if battery won't charge (common problem with Dell laptops) when either IC chip is going bad or some mosfets
Thank you for this very well explained video. Perhaps a part 2 where you explain on the battery side of the BQ24780S the function of phase, Hi and Lo mossfet and how a laptop can work on battery while there is a short on the adapter or two protection mosfet side ? Much appreciated. Very best regards.
Thank you! Amazing theory, story and tips. Cant be better! You gave me tips to troubleshoot why my HP motherboard is not starting and charging light is flashing!!
Thankyou, I've got a laptop that i was given that I was told had a "bad" motherboard. Everything I've been told points to this component having failed on the motherboard. This gives me a much better understanding of how the logic of this thing works and where to start with figuring everything out with it.
please keep scl and sda separate. you make it look like they are looped to smdata. In any case, you're doing a really good work. your videos are quite helpful to me as a professional
Thank you for such excellent explanations of these chips/circuits. It would be interesting to see how you would diagnose a laptop that powers on for 3-6 seconds then powers off. I have an Acer Predator Helios 300 that does that. The challenge is figuring out why EN1 drops out after 3-6 seconds when the KBC MAINPWON is always 3.3v and 3V_EN_R is always 0v? I need to spend more time understanding how the power controller, KBC and PCH interact during start-up. Are there any references that you can recommend (besides datasheets)? Perhaps after reviewing your KBC and power controller videos (and notes I made summarizing them) it will become clearer.
Thanks for information and tips ! I have a UX330CA motherboard (Asus) . I plug in my Lab Power Supply at and it led flashes 2 white blinks then shuts off. The moment it flashes white led blink , I measure at the input MOSFETS , current sensor 19V and also the 3.3V & 5V at the Coils .Also I Measure the input Voltage of the BQ24780S in pin VCC 19V which its present even after the 3-4 sec which it flashes White Led . Also the same goes for the 6V RGen it stays. The ACOK shows 5V for the 2 flashes one for each! And the ACDRV shows the 24V for the two flashes , one for Each.I found a SMD shorted resistor close to the ACOK which I change to 10K (I saw the typical application Schematic on Datasheet) and still no change.I am checking around the charger IC for shorted components! Any ideas ?
Thanks , really good video. I have one Acer when I plug the battery nothing works ... I didn't find the problem yet .. now I have more info due to your video :)
My friend i love this.. so help full would be nice for a full video on all the pins maybe make a check list so we can follow steps when checking keep up the great woRK!!
Very simple and informative , I am lucky, this is the general idea and design of charging sercuit but you forget id pin in HP and dell which is very important .
hi there thanks for the detailed information I have a lenovo laptop which use this IC and the laptop works on battery, works on batter + charger plugged but does not work with charger plugged and battery unplugged (maybe normal? ) On Battery plugged+ charger plugged the laptop shows as charging but it is sucking almost no current from charger (if computer shut down, if on, it will suck around 0.8A which is what the MB uses to run (so it runs on charger not on battery). As a result, laptop runs fine but battery charges extremely slow, almost no charge. did replace the low and high side mosfets (high one was shorted) but still same result. When I look at phase pin, on an oscilloscope I see a signal going from 0V to around 20V , very sharp peak to 20V and 0V, most of the cycle time being on around battery voltage. So it appears like mosftet are driven for a very short time causing too low current, voltage on the output to battery for it to charge properly. could you help with any advices? (I checked also ILIM pin, it has around 0.8V, shorted it to 3.3V (which should disable the limit and only got like 0.2 amps being drawn from charger)) Could it be that the ic is faulty? Or maybe it gets a limit on the SMBUS? (though, no error in OS (ubuntu with a live usb stick), shows as charging, charger light on and flashes very rare as mentioned in manual) Thank you very much
Hello brother Almost all laptops will work with charger plugged battery unplugged, but I am not sure if the one you have is a bit different Did you try and replace the battery because it communicates with the ic through the SMBus, so it might be faulty and / or it sends wrong signals about its status. Also, the ic might not drive the high and low Mosfets correctly, So if possible, replace the ic just to make sure
Thank you so much for this video. I think my laptop is experiencing this exact problem. Hp envy touch smart 14". bq blown out. Laptop working on battery but never works with charger. Can you know the rating and spefic bq of this?
Your motherboard charging IC is Bq24715 if I am not mistaken This is from HP Envy TouchSmart M6 LA-9315P motherboard But please check it yourself. If the IC is blown and you can't read it the you need to find your motherboard number and search for a schematics to get the IC numbering
Extremely helpful, i have laptop working with battery and working with ac only too but not charging battery and on battery connector it is providing 4v only but battery needs at least 7.6v. any idea what could be the cause. It is BQ24781
It might be because the battery voltage is too low and that is why it doesn't charge any more.. Try charging it externally first to around 10v and the install it and check it might work
أهلا أخي أكيد عندك ١٩ فولت بعد الموسفيت الاول والثاني لأن إذا ١٩ فولت موجود بعد الموسفيت الثاني المفترض يشتغل عندك الجهاز حتى لو ما كانت موجوده ٦ فولت REGN
@@FixTronics هلا بك مشكووور على الرد لا اخي موجود قبل الموسفيت الثاني لكن الفولت على gate الموسفيت الاول 18 فولت هل يمكن توصيل سلك 19 فولت الى نقطة بعد الموسفيت الثاني ام هناك شورت يمنع الايسي من اعطاء acdrv
العفو أخي إذاً عندك شورت في الموسفيت الاول تأكد منه بإستخدام ملتيميتر S -->D S-->G D-->G وتأكد بأنه لا يوجد شورت بعد الموسفيت الثاني مع ال Ground إذا لا يوجد شورت بعد الموسفيت الثاني نعم بإمكانك تستخدم سلك مكان الموسفيت الثاني وسيعمل الجهاز ولكن البطارية لن تشحن
Please explain laptop is only working without battery when connect the battery laptop does not power up. 10:37 on phase there is no short but it is only producing 8v where my battery voltage rating is 15.4v. so the problem is laptop only works when battery is disconnected when battery is connected laptop does not power up at all. i have replace the bq chip but everything is still same. any help please...
10:20 i encountered similar problem, it was vice versa when laptop plugin on adapter it works but it doesn't work with battery. i checked battery and it was fine so it is probably this kind charging IC faulty.
It might be the charging IC but there are other possibilities. Check the Battery Mosfet and check the data bus lines at the battery connector (should be 3.3v). If the battery is fully discharged try charging it with external power supply first
good explanation and very detail. i have a problem with my battery.. 19V is present.. but the voltage to the battery is very low about 3-4V... and when plug in the battery,, it drop to 1V.. ACDRV = 26V and main resistor produced 19V is present. RGN = 6V ACOK =3.3V any idea? bad battery?
It looks like you have a completely discharged battery. If you have a power supply try recharging it externally for a while and then plug it back to the laptop an connect the adapter. If it start to charge, then leave it till its fully charged You may still need to replace it anyway if it is old and weak already.. If all the above did not help then try a new battery replacement
@@FixTronics ok i had recharge it for 15 minutes.. and plug in into the laptop.. and it works without DC in.. plug in the charger.. the charging led now turn on... now put it on charging (turn off laptop) for 1hr.. will update if it still have provlem
You are welcome brother The ACDET is connected via a voltage divider which sets its voltage. Normally 2.8v is correct voltage, but you can calculate the output voltage of the voltage divider using this equation Vout=Vin*(R2/R1+R2)
Hye all i need help, If my laptop says battery not detected, but when charging can turn on pc, which part only actually problem? Then indicator light for charging not turn on. Battery new already installed (build in battery). Lenovo ThinkPad p1.
Thank you. Very informative. Question pls sir. Assuming a good battery, but not charging when plugged in to power. Charger can power laptop on its own. battery can power laptop on its own. together, battery doesn't discharge or charge, but laptop works fine. Where to check for this?
Isn't it strange, that I have another laptop with the exact same problem as I described above, but replacing the IC didn't fix this one. It almost trickle charges the battery when plugged in (like the voltage isn't enough to charge the battery, but its enough to stop the battery discharging). Might give up on this one.
Hi, Can you help me and give some hints? I have a laptop motherboard with this exact chip, but not powering on, completely dead. The charger IC gets 19V VCC, 6V REGN is present. ACDET is 1.3V, no voltage on ACDRV. Input mosfets seem to be fine. Many thanks!
Hi Check the ACDET if it is correct or not by calculating the voltage divider in which its connected to. I think it should be 2.4v if I am not mistaken
Great video ! I have a case, I replaced the BQ and the laptop is working fine on both battery and charger. I can see the charging sign in windows but the battery is not taking any current (10mA) therefore it is not charging. The charging light is blinking so I though it was a faulty battery so I bought a new one but unfortunately the batery is still not charging. I checked every pin of the BQ, PIN 1 : 19.3V Pin 2 : 19.3V Pin 5 : 3V Pin 6: 2.6V Pin 11: 3.21v Pin 12: 3.23v Pin 19 : 11.31V Pin 20 : 11.31V PIN 24: 6V The battery connector is good and I checked every pins as well. Everything looks fine, how can you explain that the laptop thinks it is charging the battery but it is not ?
Hello friend I don't see 25v ACDRV in the readings you provided.. You might have a shorted ACFET.. Please check both first and second Mosfets for short (S=>D & S=>G & D=>G).
Did you try replacing the battery with a good know working one If yes but the problem still persist then check the Battery Mosfet and Battery charging Mosfets and if they all are good then try replacing the BQ ic
If you are measuring both pins with each other, then yes you will see a short, because they are connected across a very low resistance (Current Sense Resistor). But if you are seeing a short on one or both ACP and ACN to ground, the you main power rail is shorted. Your BQ chip is most likely to be ok...
Laptop works on charger, works off battery. See percentage but battery percentage wont go up during charging, 0 amp draw yet will say charging. Any indication? Dell machine.
나는이 문제를 일으키는 충전 IC가 아니라고 생각합니다. 노트북에 rtc 배터리가 없고 대신 주 배터리를 사용하는 경우 주 배터리가 매우 부족하면 BIOS가 엉망이 되어 배터리를 분리하고 배터리를 분리할 때까지 노트북이 켜지지 않을 수 있습니다. 바이오스를 재설정하면 노트북이 작동합니다. 또한 충전 IC가 양호하더라도 전압이 일정 수준 이하로 떨어지면 배터리가 충전되지 않습니다. 랩 벤치 전원 공급 장치로 배터리를 재충전하고 랩톱에 연결하고 전원을 켜거나 잘 알려진 다른 배터리를 사용해 보십시오. 이것이 도움이 되기를 바랍니다.
@@FixTronics 조언 감사합니다. 저도 처음에 배터리 문제인 것 같아서 배터리는 새제품으로 교환을 했습니다. 배터리가 작동하니까 켜진다는 걸 그때 알았습니다. 그런데도 충전이 전혀 되지 않습니다. 처음 구입당시의 배터리 잔량으로만 전원이 켜지는 상태이고 배터리 잔량이 0이되면 충전기를 꽂아도 켜지지 않습니다. 배터리가 0이 되면 배터리를 제거해야만 어댑터로 전원이 켜지고, CPU의 성능제한 상태로 작동이 되어서 매우 느립니다.
bq24780s와 매우 다른 bq25700a 데이터시트를 살펴보았습니다. 시스템이 배터리가 연결된 상태에서 전원이 켜지지 않고 배터리 없이 전원이 켜지는 것이 이상합니다. 아마도 IC 자체가 이 문제를 일으키는 것일 수 있습니다. 교체를 시도하고 해결되는지 확인하십시오.
datasheet regn said is 0.6v and my question is can this ic kill every thing the power couldn't pass the first Mosfet form the charger? the Mosfet looks good no short on it.
Hi. I have Lenovo X1 with this circuit, computer work ok with charger and battery, detect charger, the charger led come up (ambar) but don't charge, I have 3,3v on ACOK, I have 6V on REGEN, could the BQ24780 is faulty? I have 3 new battery all do the same, but work in other laptop, have 0,2v on batdrv, this is not right?
Hi All voltages you mentioned are correct and about BATDRV, yes it is correct as long as the adapter is connected and it should go to around 20v or so when the adapter is disconnected, and you said the laptop do work on battery, so that confirms your BATDRV is correct when the adapter is disconnected.. You should check the HIDRV and LODRV when the adabter is connected. Those HIDRV and LODRV are responsible for charging the battery by driving two Mosfets. The LODRV source pins are connected to GND and the HIDRV drain pins are connected to 19v The source of HIDRV Mosfet and drain of LODRV Mosfet are connected together, and this goes to the battery and to pin phase of the BQ ic
Hi, i have a BQ25A and it doesnt want to give the ACDRIVE 25V to my mosfets. The ACOK is 3V, the 6V regen is OK and there’s no shorts anywhere. Does it mean the BQ chip itself is defect?
@@FixTronics Thanks mate! After watching your video again, I did some more measurements and found that the 2nd input MOSFET was only 5 Ohms. After replacing it, BQ chips works fine again.
☺ I have a Asus X556U With Bat Mosfet burned, and BQ24780S off, I have change both, computer start to work ok, but it have a 7,6V battery, and I have 16v (phase) and on + of battery connector on board. If I install the battery the batt fet burn, I have tested with a new battery and do the same, I think the problema is the 16V on circuit with a 7.6v batt, the max voltagem must be 8,5v (I think). (note I install for second time a BQ24780s)
That is strange Ok try removing the high side Mosfet and check for that 16v at phase pin If it still there then remove the battery Mosfet and check again You might have fitted a faulty one because there is no way for that 16v to reach phase pin except from those two Mosfets
hi good day i have a a problem when a check voltage in ACDRV is fluctuating around 3-4 volts where should be 26 volts and REGN is 6v but the ACOK is 0 v is where i should start to check i ready replace a ic same problem
Hi Try and check the two first Mosfets (ACFET and RBFET) for shorts and check the resistors at the ACDRV line. ACOK will only be generated when the 19v passes the first two Mosfets
Hi friend If your laptop is charging or at least tries to charge then the charging circuit is most likely to be good unless there is something wrong with ILIM charge and discharge current limit. Try first and change the battery if possible, because the battery itself can start and stop the charging process through the serial communication with the EC chip
Sir is there any difference between ISL9520HRTZW418UB and ISL9520HRTZW4235W ? Does last digits make any difference. Can I replace 1st with 2nd in my dell laptop?
You're something special - i watched so many videos trying to understand how this chip is working- yours was the only one that broke it to details and explained the whole process, from A to Z- thank you so much for you time to make this video and hope you can make other videos explaining what to do if battery won't charge (common problem with Dell laptops) when either IC chip is going bad or some mosfets
❤
I agree with him. You vídeo is the best I have seen. And I study laptops for years. Thank you.
Thank you so much brother
Very informative. I have always wanted to know more about the charging ic. This will be a good start. Thanks
Thank you for this very well explained video. Perhaps a part 2 where you explain on the battery side of the BQ24780S the function of phase, Hi and Lo mossfet and how a laptop can work on battery while there is a short on the adapter or two protection mosfet side ? Much appreciated. Very best regards.
I'd like to know too as this is where I have a problem. I'm seeing 8v to the battery and 0.2v when battery is connected
Thank you for the time you took to create such a nice video. I appreciate that you share your knowledge with others.
Thank you! Amazing theory, story and tips. Cant be better! You gave me tips to troubleshoot why my HP motherboard is not starting and charging light is flashing!!
You welcome brother
I am glad you found my video helpful for you.
I wish you all the best .
Thankyou, I've got a laptop that i was given that I was told had a "bad" motherboard. Everything I've been told points to this component having failed on the motherboard. This gives me a much better understanding of how the logic of this thing works and where to start with figuring everything out with it.
You are welcome brother
I wish you all the best
You explain well and thanks for the example of the laptop you encountered working with the battery . Thank you
You are welcome dear friend
Wow! Amazing Explain and interesting helpfull video. Many more thanks ❤️❤️ Boss.
please keep scl and sda separate. you make it look like they are looped to smdata. In any case, you're doing a really good work. your videos are quite helpful to me as a professional
Thank you so much for making this video, we’re all looking forward to your next video .. 🙏
Thank you for such excellent explanations of these chips/circuits. It would be interesting to see how you would diagnose a laptop that powers on for 3-6 seconds then powers off.
I have an Acer Predator Helios 300 that does that. The challenge is figuring out why EN1 drops out after 3-6 seconds when the KBC MAINPWON is always 3.3v and 3V_EN_R is always 0v? I need to spend more time understanding how the power controller, KBC and PCH interact during start-up. Are there any references that you can recommend (besides datasheets)?
Perhaps after reviewing your KBC and power controller videos (and notes I made summarizing them) it will become clearer.
Excellent explanation. Thumbs up sir
Thanks for information and tips ! I have a UX330CA motherboard (Asus) . I plug in my Lab Power Supply at and it led flashes 2 white blinks then shuts off. The moment it flashes white led blink , I measure at the input MOSFETS , current sensor 19V and also the 3.3V & 5V at the Coils .Also I Measure the input Voltage of the BQ24780S in pin VCC 19V which its present even after the 3-4 sec which it flashes White Led . Also the same goes for the 6V RGen it stays. The ACOK shows 5V for the 2 flashes one for each! And the ACDRV shows the 24V for the two flashes , one for Each.I found a SMD shorted resistor close to the ACOK which I change to 10K (I saw the typical application Schematic on Datasheet) and still no change.I am checking around the charger IC for shorted components! Any ideas ?
Thanks , really good video. I have one Acer when I plug the battery nothing works ... I didn't find the problem yet .. now I have more info due to your video :)
My friend i love this.. so help full would be nice for a full video on all the pins maybe make a check list so we can follow steps when checking keep up the great woRK!!
I have just watched your video, it is great, thank you for sharing your knowledge
You are welcome brother
Nice work, Thanks so lot
Very great video,Already used this information to repair a charging issue on a HP laptop,keep the videos coming.
Glad you found it helpful
Thanks👍🏻
What was the issue?
Excellent review.
osm explanation thank you sir
Very simple and informative , I am lucky, this is the general idea and design of charging sercuit but you forget id pin in HP and dell which is very important .
ID pin is rather part of EC circuit
it is a very easy explain Thanks
Muy bien explicado maestro,gracias.
Great👍🏾pls. Explain all sections of laptop👍🏾
Thanks you, you explain well. Please can you explain us the 3v/5v ic also ?
Great video sir very informative
Thank you so much brother
Thanks for the information..
great video
I learnt a lot in this video i can't explain.
Great video, thanks bro.
You welcome bro
Thanku for making these kinds of video sir , learning from you , also plzz make topic on sections like rtc , vin , vcc ldo
You are welcome brother
I will try hard to do my best
Thank you so much
Thanks for the valuable information
U R welcome brother
Thank you, very helpful video.
You welcome brother
Thank you very much 😇😇
thanks you a lot for this video explaination , was very usefull :)
U welcome brother
Thank you Sir, very informative
U welcome brother
Saudações do Brasil. Parabéns pelo vídeo! Com certeza me ajudou muito. Obrigado!
Thank you good job
greatvideo
Merci beaucouppour ces bonnes explications
tu es le bienvenu cher ami😊⚘
Good job
Good contents 👍
Thanks
Good 👍
Very helpfull
HI Sir i'm fan of your channel I love the way you teach and may I request a no display laptop that you repairing Thank you! keep it up
U welcome brother
Sure as soon as I get a laptop with this issue I will make a video of it
Thank you so much
Thank you, can you explain the LDO IC, maybe the RAM power IC, GFX IC?
best well explain sir
Thank you my dear 😊⚘
you're awesome
Very Informative, I would like to see a similar diagram for the BQ2475argrr please, (slightly Different) to the BQ24780s
I will have a look at it
Thanks brother
Please please keep making these kinda videos please...
I don't have much time these days
But I will continue doing these kind of videos
THNX BROTHER NİCE VİDEO
thank you!!
wow... thanks sir
U welcome brother ^_^
Very Good video. Please increase or double your voice level.
Thank u a lot
U welcome brother
So how does the super Io get it's power to give the ok go ahead signal?
Thank u
thank you sir
You welcome brother
hi there
thanks for the detailed information
I have a lenovo laptop which use this IC and the laptop works on battery, works on batter + charger plugged but does not work with charger plugged and battery unplugged (maybe normal? )
On Battery plugged+ charger plugged the laptop shows as charging but it is sucking almost no current from charger (if computer shut down, if on, it will suck around 0.8A which is what the MB uses to run (so it runs on charger not on battery). As a result, laptop runs fine but battery charges extremely slow, almost no charge.
did replace the low and high side mosfets (high one was shorted) but still same result. When I look at phase pin, on an oscilloscope I see a signal going from 0V to around 20V , very sharp peak to 20V and 0V, most of the cycle time being on around battery voltage. So it appears like mosftet are driven for a very short time causing too low current, voltage on the output to battery for it to charge properly.
could you help with any advices? (I checked also ILIM pin, it has around 0.8V, shorted it to 3.3V (which should disable the limit and only got like 0.2 amps being drawn from charger))
Could it be that the ic is faulty? Or maybe it gets a limit on the SMBUS? (though, no error in OS (ubuntu with a live usb stick), shows as charging, charger light on and flashes very rare as mentioned in manual)
Thank you very much
Hello brother
Almost all laptops will work with charger plugged battery unplugged, but I am not sure if the one you have is a bit different
Did you try and replace the battery because it communicates with the ic through the SMBus, so it might be faulty and / or it sends wrong signals about its status.
Also, the ic might not drive the high and low Mosfets correctly, So if possible, replace the ic just to make sure
thanks pro
gracias pana, todo esta mas claro ahora
You welcome bro
Thank you so much for this video. I think my laptop is experiencing this exact problem. Hp envy touch smart 14". bq blown out. Laptop working on battery but never works with charger. Can you know the rating and spefic bq of this?
Your motherboard charging IC is Bq24715 if I am not mistaken
This is from HP Envy TouchSmart M6 LA-9315P motherboard
But please check it yourself.
If the IC is blown and you can't read it the you need to find your motherboard number and search for a schematics to get the IC numbering
thank you very much, kind man. i want to modify my laptop to use all power from 100w USB C Power Supply and not resort to draining the battery
Extremely helpful, i have laptop working with battery and working with ac only too but not charging battery and on battery connector it is providing 4v only but battery needs at least 7.6v. any idea what could be the cause. It is BQ24781
It might be because the battery voltage is too low and that is why it doesn't charge any more..
Try charging it externally first to around 10v and the install it and check it might work
I prefer some description about charging pump inside this ic in order idea being clearly.
Here it is brother
ua-cam.com/video/lHpiHePUzKg/v-deo.html
Brother, can you explaining about IC intersil 88739A, please?? 🙏
thank you bro kindly do one video on power sequence of laptop moyher board thankx
I are welcome brother
I will try to do it in future videos
It seems that the PROCHOT is an output signal?
Where can i get the full forms ACDET - Ac detect like this & Good video thankyou
You can use the chip datasheet
الله يعطيك العافية مشكووور ما قصرت
عندي جهاز hp فيه مشكلة ميت فحصت هذي الايسي بس كله تمام الا regn ماطلعتلي فولت مع انه 19 فولت موجودة بعد الموسفيتات
أهلا أخي
أكيد عندك ١٩ فولت بعد الموسفيت الاول والثاني
لأن إذا ١٩ فولت موجود بعد الموسفيت الثاني المفترض يشتغل عندك الجهاز حتى لو ما كانت موجوده ٦ فولت REGN
@@FixTronics هلا بك
مشكووور على الرد
لا اخي موجود قبل الموسفيت الثاني لكن الفولت على gate الموسفيت الاول 18 فولت
هل يمكن توصيل سلك 19 فولت الى نقطة بعد الموسفيت الثاني ام هناك شورت يمنع الايسي من اعطاء acdrv
العفو أخي
إذاً عندك شورت في الموسفيت الاول
تأكد منه بإستخدام ملتيميتر
S -->D
S-->G
D-->G
وتأكد بأنه لا يوجد شورت بعد الموسفيت الثاني مع ال Ground
إذا لا يوجد شورت بعد الموسفيت الثاني نعم بإمكانك تستخدم سلك مكان الموسفيت الثاني وسيعمل الجهاز ولكن البطارية لن تشحن
Please explain laptop is only working without battery when connect the battery laptop does not power up. 10:37 on phase there is no short but it is only producing 8v where my battery voltage rating is 15.4v. so the problem is laptop only works when battery is disconnected when battery is connected laptop does not power up at all. i have replace the bq chip but everything is still same. any help please...
10:20 i encountered similar problem, it was vice versa when laptop plugin on adapter it works but it doesn't work with battery. i checked battery and it was fine so it is probably this kind charging IC faulty.
It might be the charging IC but there are other possibilities. Check the Battery Mosfet and check the data bus lines at the battery connector (should be 3.3v).
If the battery is fully discharged try charging it with external power supply first
Hi friend thanks for another informative video
good explanation and very detail.
i have a problem with my battery.. 19V is present.. but the voltage to the battery is very low about 3-4V... and when plug in the battery,, it drop to 1V..
ACDRV = 26V and main resistor produced 19V is present.
RGN = 6V
ACOK =3.3V
any idea? bad battery?
It looks like you have a completely discharged battery.
If you have a power supply try recharging it externally for a while and then plug it back to the laptop an connect the adapter.
If it start to charge, then leave it till its fully charged
You may still need to replace it anyway if it is old and weak already..
If all the above did not help then try a new battery replacement
@@FixTronics ok i had recharge it for 15 minutes.. and plug in into the laptop.. and it works without DC in.. plug in the charger.. the charging led now turn on... now put it on charging (turn off laptop) for 1hr.. will update if it still have provlem
@@FixTronics do u know the minimum voltage that the battery should have for the laptop able to recharge it?
update..after fully charging using DC power supply.. the battery voltage when plug in... drop below 10V and laptop turn off... about 20-30s
THANK YOUUU VERY MUCH ...... PLEASE I HAVE A QUESTION .... WHAT IS THE NORMAL VOLTAGE FOR THE ACDET ..... IN MY IC I FOUND IT 2.8 V .... IS IT NORMAL?
You are welcome brother
The ACDET is connected via a voltage divider which sets its voltage.
Normally 2.8v is correct voltage, but you can calculate the output voltage of the voltage divider using this equation
Vout=Vin*(R2/R1+R2)
Hye all i need help, If my laptop says battery not detected, but when charging can turn on pc, which part only actually problem? Then indicator light for charging not turn on. Battery new already installed (build in battery). Lenovo ThinkPad p1.
Thank you. Very informative. Question pls sir. Assuming a good battery, but not charging when plugged in to power. Charger can power laptop on its own. battery can power laptop on its own. together, battery doesn't discharge or charge, but laptop works fine. Where to check for this?
Ended up being a fault BQ chip. Replaced and working
Great
Glad you sorted it out
Isn't it strange, that I have another laptop with the exact same problem as I described above, but replacing the IC didn't fix this one. It almost trickle charges the battery when plugged in (like the voltage isn't enough to charge the battery, but its enough to stop the battery discharging). Might give up on this one.
@@wayneharvett6170 sometimes these BQ Ic chips came faulty even if it was new, so try replacing it ones more
Hi, Can you help me and give some hints? I have a laptop motherboard with this exact chip, but not powering on, completely dead. The charger IC gets 19V VCC, 6V REGN is present. ACDET is 1.3V, no voltage on ACDRV. Input mosfets seem to be fine. Many thanks!
Hi
Check the ACDET if it is correct or not by calculating the voltage divider in which its connected to.
I think it should be 2.4v if I am not mistaken
Great video !
I have a case, I replaced the BQ and the laptop is working fine on both battery and charger. I can see the charging sign in windows but the battery is not taking any current (10mA) therefore it is not charging. The charging light is blinking so I though it was a faulty battery so I bought a new one but unfortunately the batery is still not charging. I checked every pin of the BQ, PIN 1 : 19.3V
Pin 2 : 19.3V
Pin 5 : 3V
Pin 6: 2.6V
Pin 11: 3.21v
Pin 12: 3.23v
Pin 19 : 11.31V
Pin 20 : 11.31V
PIN 24: 6V
The battery connector is good and I checked every pins as well.
Everything looks fine, how can you explain that the laptop thinks it is charging the battery but it is not ?
Hello friend
I don't see 25v ACDRV in the readings you provided..
You might have a shorted ACFET..
Please check both first and second Mosfets for short (S=>D & S=>G & D=>G).
@@FixTronics Hello my friend,
ACDRV : 24.V
And both mofset looks good :/
@@kader131
Try and check the charging Mosfets
If they are ok try updating you drivers especially the bios and ec firmware
@@FixTronics I updated everything and is still not charging :/
I am thinking about to change the BQ again
Can you explain the same for the BQ25 Battery Charge Controller. Please
Hi
BQ25 is a BQ24 but they write the last two digits Instead of the first two. For example BQ25 is BQ24725 or BQ25A is BQ24725A
Hi have a hp laptop when the battery is in the bq24780s gets hot and turned off.. ic bad ? No shorts but
Did you try replacing the battery with a good know working one
If yes but the problem still persist then check the Battery Mosfet and Battery charging Mosfets and if they all are good then try replacing the BQ ic
Thanks
U welcome brother
I have a different problem, a short circuit occurs on the acn and acp pin ICs, is the IC damaged?
If you are measuring both pins with each other, then yes you will see a short, because they are connected across a very low resistance (Current Sense Resistor).
But if you are seeing a short on one or both ACP and ACN to ground, the you main power rail is shorted.
Your BQ chip is most likely to be ok...
Laptop works on charger, works off battery. See percentage but battery percentage wont go up during charging, 0 amp draw yet will say charging. Any indication? Dell machine.
You may have a faulty battery or the battery voltage is too low
레노버 노트북 E14모델이고, bq25700A IC가 있습니다. 배터리 충전이 되지 않고 배터리 잔량이 없으면 충전기로도 켜지지 않습니다. 배터리를 제거하면 충전기로 전원이 켜지는데, IC 문제일까요?
나는이 문제를 일으키는 충전 IC가 아니라고 생각합니다. 노트북에 rtc 배터리가 없고 대신 주 배터리를 사용하는 경우 주 배터리가 매우 부족하면 BIOS가 엉망이 되어 배터리를 분리하고 배터리를 분리할 때까지 노트북이 켜지지 않을 수 있습니다. 바이오스를 재설정하면 노트북이 작동합니다. 또한 충전 IC가 양호하더라도 전압이 일정 수준 이하로 떨어지면 배터리가 충전되지 않습니다. 랩 벤치 전원 공급 장치로 배터리를 재충전하고 랩톱에 연결하고 전원을 켜거나 잘 알려진 다른 배터리를 사용해 보십시오. 이것이 도움이 되기를 바랍니다.
@@FixTronics 조언 감사합니다. 저도 처음에 배터리 문제인 것 같아서 배터리는 새제품으로 교환을 했습니다. 배터리가 작동하니까 켜진다는 걸 그때 알았습니다. 그런데도 충전이 전혀 되지 않습니다. 처음 구입당시의 배터리 잔량으로만 전원이 켜지는 상태이고 배터리 잔량이 0이되면 충전기를 꽂아도 켜지지 않습니다. 배터리가 0이 되면 배터리를 제거해야만 어댑터로 전원이 켜지고, CPU의 성능제한 상태로 작동이 되어서 매우 느립니다.
bq24780s와 매우 다른 bq25700a 데이터시트를 살펴보았습니다. 시스템이 배터리가 연결된 상태에서 전원이 켜지지 않고 배터리 없이 전원이 켜지는 것이 이상합니다. 아마도 IC 자체가 이 문제를 일으키는 것일 수 있습니다. 교체를 시도하고 해결되는지 확인하십시오.
@@FixTronics 감사합니다.. 시도해보겠습니다. 하지만 IC를 구하는게 쉽지 않네요.
datasheet regn said is 0.6v and my question is can this ic kill every thing the power couldn't pass the first Mosfet form the charger? the Mosfet looks good no short on it.
REGN must be 6v.
Yes this IC can stop your laptop from turning on if it is faulty or if it detected a short within the motherboard
@@FixTronics No short but I accidentally shorted mosfet with cap with my fat prob!😁 thank you sir! you helped a lot. keep it up! 🙏
You welcome brother
Glad you knew the issue 🙂👍🏻
All the best...
Hello,
Thank you, but don't waste your time. Do you know the IT8225VG-128? Your explanations help me a lot. Kind regards
Hi. I have Lenovo X1 with this circuit, computer work ok with charger and battery, detect charger, the charger led come up (ambar) but don't charge, I have 3,3v on ACOK, I have 6V on REGEN, could the BQ24780 is faulty? I have 3 new battery all do the same, but work in other laptop, have 0,2v on batdrv, this is not right?
Hi
All voltages you mentioned are correct
and about BATDRV, yes it is correct as long as the adapter is connected and it should go to around 20v or so when the adapter is disconnected, and you said the laptop do work on battery, so that confirms your BATDRV is correct when the adapter is disconnected..
You should check the HIDRV and LODRV when the adabter is connected.
Those HIDRV and LODRV are responsible for charging the battery by driving two Mosfets.
The LODRV source pins are connected to GND and the HIDRV drain pins are connected to 19v
The source of HIDRV Mosfet and drain of LODRV Mosfet are connected together, and this goes to the battery and to pin phase of the BQ ic
@@FixTronics I change de BQ24780S and computer charge normaly and work ok now
Hi, i have a BQ25A and it doesnt want to give the ACDRIVE 25V to my mosfets. The ACOK is 3V, the 6V regen is OK and there’s no shorts anywhere. Does it mean the BQ chip itself is defect?
Please check if you have a resistor in between the Mosfets gate and the BQ ic.
Check it if it is open circuit if not replace the BQ ic
@@FixTronics Thanks mate! After watching your video again, I did some more measurements and found that the 2nd input MOSFET was only 5 Ohms. After replacing it, BQ chips works fine again.
@wouterhimschoot
Hi friend
Glad to hear that you got it fixed and I am more happy to have you in my channel
Thank you so much
Bonjour,
Je rechereche le schéma pour un laptop Asus Rog Strix carte mere G531W? MERCI
Salut, je vais essayer de le trouver pour vous et si je pouvais et je le partagerai avec vous
thanks
U welcome brother
Hello sir i have lenovo t460 laptop working well on adapter but battery percentage not increasing,,
Hi friend
Its either the battery itself or the charging IC
☺ I have a Asus X556U With Bat Mosfet burned, and BQ24780S off, I have change both, computer start to work ok, but it have a 7,6V battery, and I have 16v (phase) and on + of battery connector on board. If I install the battery the batt fet burn, I have tested with a new battery and do the same, I think the problema is the 16V on circuit with a 7.6v batt, the max voltagem must be 8,5v (I think). (note I install for second time a BQ24780s)
Hi friend
Its most likely you have a bad high side Mosfet
Try replacing it..
@@FixTronics Hi, thank's for your attention, I have change all Mosfet, low and hi side, and battery charge mosfet too... problem remains
That is strange
Ok try removing the high side Mosfet and check for that 16v at phase pin
If it still there then remove the battery Mosfet and check again
You might have fitted a faulty one because there is no way for that 16v to reach phase pin except from those two Mosfets
@@FixTronics Without Hi fet 0.8v. if I remove 3 fets Hi, LO and bat drv I have 8,2V...🙄
@@FixTronics I have replace the two QM1830M3 (high and LOW) again...
I have similar problem. But it works on the adapter, charges the battery but wil not work on the battery. Can't find the problem. IdeaPad 330X 15AAR
Check the BATFET Mosfet. The Mosfet that connects the battery to the main power rail
Please do Pluged in no charging
hi good day
i have a a problem when a check voltage in ACDRV is fluctuating around 3-4 volts where should be 26 volts and REGN is 6v but the ACOK is 0 v is where i should start to check i ready replace a ic same problem
Hi
Try and check the two first Mosfets (ACFET and RBFET) for shorts and check the resistors at the ACDRV line.
ACOK will only be generated when the 19v passes the first two Mosfets
@@FixTronics Thanks
Благодарю! Помог найти неисправность
добро пожаловать, рад, что вы нашли это полезным
I Have a Toshiba won't start when battery connected. I'm guessing is the bat MOSFETs .
You are right..
It might be the Bat Mosfet or the charging Ic is not driving it
Hi I have 6v at regn and the battery start charging then stops. I don't know why
Hi friend
If your laptop is charging or at least tries to charge then the charging circuit is most likely to be good unless there is something wrong with ILIM charge and discharge current limit.
Try first and change the battery if possible, because the battery itself can start and stop the charging process through the serial communication with the EC chip
Sir is there any difference between ISL9520HRTZW418UB and ISL9520HRTZW4235W ? Does last digits make any difference. Can I replace 1st with 2nd in my dell laptop?
Hi friend
Yes they are the same..
@@FixTronics Thanks for the information.