Asus Vivobook X512 not charging - Steps to take checking the charging circuit

hello s back and this time this time we have a nice t-shirt huh so what do you think about this uh I got a present on this morning from uh one uh from one one of this channel subscriber bill so I'll say thank you Bill for the for the t-shirt and for the cup yeah we have the cup I will show you the cup on the tomorrow live stream tomorrow is Sunday right yeah so what do we have here we have a nice level to H check here ryzen 7 and radon Graphics Asus Viv book now the problem with this one this laptop is coming from a computer shop okay now the computer shop semi2 laptop so we are looking right now Asus Viv book fold power Zone does not charge also the computer shop sent a present bards for you for parts and this is a MacBook board work pretty nice people you know what I mean that's how you send a job you send a job and you send a present with the job yeah I mean I I don't understand why the people are so nice in me anyway the problem with this laptop like we seen the laptop it is coming on let's see if it's coming on I can't see any no I can't see anything pressing the power button nothing happened let's plug a charger in check 19 volts good let's plug the charger and the laptop probably it's on or is charging we have the charging light here and the power on light so I believe the the actually the laptop it is on yeah you see the laptop it is on but the question is the laptop is charging that's the question huh less power off the laptop yeah we have Windows let's power off oh it's a brand new windows okay that's fine so we power off the laptop and the laptop is taking no power and that's not normal right I mean the battery should charge right pressing the power button unplugging the charger and the power goes off let's open the laptop quickly now what we are checking first first we are checking this is Asus if we don't have that uh PNY charging port yeah I se Acer and Asus charging port where actually the charging port has a pin each which it will detect if the if the power connector is all plugged in then we're going to check the first and the second mosfet okay that's a must okay so the laptop is open we have a nice motherboard and yeah indeed we have that tricky charging import so check here yeah on the charge import you have minus okay ground and you have plus and then you have two pins one is ground and one is that pin which it will sense if the connector is all plugged in so what I'm going to do and I will show you how to check you plug the charger okay and the laptop is coming on straight away you can see the uh you can see the lights here the laptop it is on let me shut down the laptop first I mean it's not even important but let's shut it down okay the laptop it is off and let's check together the voltage on that particular pin so on this pin is zero okay and on this spin e is zero LOL okay so the problem is on the charging port and of course here we have 199 good that's that's okay that's not a problem that's not issue so what do we have to check now is the first mosfet and second mosfet so here we have a big Power is not here okay we have to take out the motherboard because I believe the first moset on the second M it's under this board okay so the board it's out we have this cable left yeah we do have check here yeah charging port we have the plus line is going to first most a second mosfet and then we have a current sensor current resistor sorry the ram we have uh on board Ram also we have uh socket yeah let's check the first two mosfets good so we have the first mosfet and the first mosfet is good lol and you have the second mosfet and the second mosfet is good the first mosfet we have 19.5 and here here we have 19.7 okay on the gates we have 25 and here we have 25 so the input circuit is fine it's no issue with the input circuit okay you know what I was wrong so actually here both pins are connected to ground yeah so here we don't have that charging port where where it will detect if the charger is all plugged in okay so on this point uh we don't have too many options left I mean what do we have here we have a diode we have the charging circuit here circuit yeah let me correct myself someone right on the chat so here we have 0er volts here you have 19 so I believe the charging circuit is good circuit sorry here you have the BQ chip but I don't think anything is faulty here I will check the the charging mosfets let's check them but this mosfet is good this mosfet is good checking the gates all good so as you can see here we have no fault so what is the problem the problem could be the battery okay sorry but how can we know if the battery is FY or not very simple let me grab the power supply okay so I will lower uh the current and the voltage yeah like that and yeah yeah that should be fine and we are coming with a power supply on the battery connector here and here and it's taking no current at all you can see and that's exactly what I said on the beginning can be a fear battery fmer issue not sure if this it's a genuine battery because I can't see any writing here maybe the writing is on the other side of the battery can be but let me take out the battery let's try have a to have a look but how can I okay how we have a screw here let me grab my uh battery analyzer and let's see what's wrong with this battery right yeah okay so we connect the battery to the nlba we have the software on the screen and the issue is one of the cell you can see so the battery it is locked has a bad balance uh we can see one cell has uh one cell has like 3.8 one cell has 1.1 now you'll say sorry play in the bin it's I use battery check on the cycle count yeah can you see the cycle count one cycle count now Computing the health of the battery now this must be must be something wrong you know actually the voltage can be a firmer error 2020 battery I don't believe this is the health of the battery with one cycle count yeah I I can't believe that no so what can be wrong here good question it's not much what we can do the only things what we can do is to open the battery and try to check the cells manually uh one cell can be like what he's saying on 1.1 volts but also can be a big fmer error so let's open the battery have a look inside okay let's try to do a incision surgical we have the plastic frame but the plastic play frame can be cut uh easily perfect now we do have access inside the cells let's check the cells so this cell has 3.8 and this cell has indeed 1.1 so we need a 3.8 volts here the plus is here minus is there let's come with some current plus minus yeah 4.7 it's about the right amount of current on this cell okay where where about therea we can see it's still a poor balance that's fine but the battery is locked let me try quickly something we have to power off reset power on good uh reip info and the charger and discharging is disabled okay let's uh unseal very cheap info we have PF status we have we have a error there you can see it uh good clear chip errors good read chip info now we have no error you can see PF status we have 0 0 0 but the charging and discharging is still disabled so I'm going to seal back the battery and power off going to battery info the battery is unlocked you can see it uh it is unlocked but the charging and discharging is still disabl that can be from a good reason and the reason is the fuse yeah so let's go and check for the fuse where we can find the battery fuse is not on this side of the board right no probably it's on the other side of the board so what do we have to do is another incision here and here and yeah the battery is open yeah we do have a fuse here you can see it that one so this is a special fuse yeah it's a fuse having a heater so the heater is connected from here to the plus here is the plus line and when the BQ chip is connecting this pin to ground the heitter it will hit the solder from inside of the fuse and it will melt it so let's open the fuse and have a look yeah the fuse the fuse is gone yeah so this is flat yeah the fuse is good no the fuse is burn here check here so you see the solder got melted here but not here only here okay that's fine so all we have to do is to sold the uh the fuse that's how the fuse is made with solder and rosing inside just a little bit of solar wire perfect yeah so now the fuse is how it was from the factory now the question is the battery Tool Work the batter is unlocked uh how we can test it very simple charge and we are start charging the battery and if we are seeing the current check there the current you can see it so actually now the battery is accepting the the charging current and you can see the current is going up you can see the blue line that's the current okay reading the battery the cells are balanced now are uh only 3 MTS difference between the cells so I believe everything it's uh it's right this time I will say let's plug the battery into the laptop and let's test it to see if it's working we done a good job or perfect like brand new ah okay the board is back in place let's plug the battery perfect let's plug the charger and probably the laptop it will come on yeah no it's not coming yeah it is on sorry it is on you can see the light here so I will shut down the laptop yeah so the laptop is off we have the charging light and we have 1.8 amps onto the battery you can see that's the charging current that's only is going into the battery 1.8 amps so the laptop it is charging fine now powering on the laptop the laptop it is coming on the current is going like over 2 amps and let's unplug the charger yeah so unplug in the charger and the battery it's holding is holding the charge obviously the battery is discharged so we have have to charge it but it is holding the charge so the batter is providing uh power to the laptop now I'm happy I help this customer this is a fix uh fixed laptop is repaired why this happen why this fold happen my opinion is probably the laptop sit uh for long time and one cell died why one cell died and not the other hard to say why because the battery has one cycle yes this this is a brand new battery it is possible the BQ chip because obviously even that power management chip need power it is possible to be connected to one cell and that's the reason why over the time one cell go discharged but I can't say that for sure okay I left it a little bit on charge let's check the voltage and we have 8.2 volts so those are two cells do mean the battery fully charged is like uh uh 8.4 volts so the laptop it is working fine I'm happy I helped this customer I will say uh thank you for watching I will put it all back together myself because there a lot of screws you know don't forget like subscribe if you like the video of course and see you on the next one bye

Channel: Electronics Repair School

Views: 19,869

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Id: j8Nw_pmdlM8

Length: 17min 54sec (1074 seconds)

Published: Sat Apr 20 2024