MacBook Air 820-00165 Not charging because of damaged SYS ONEWIRE Circuit

okay I'll deal with that all right so today we have ourselves here in MacBook Pro 13 let's take that step back and edit alright so today we have ourselves in MacBook Air 13-inch this one's a 82000 165 this one came in here for not booting so initially I opened up this MacBook in front of the customer and noticed that there was a little bit of corrosion on the SPI JTAG terminal so I'm thinking that's one of the reasons why this isn't turning on but now we're also not getting a green light on our Mac safe so that tells me that something's wrong with our sister yep I've gone ahead and removed the JTAG just to eliminate that being an issue still not turning on so we may have had some damage done to our SPI ROM our BIOS but let's go ahead and just start from the basic so I'm gonna plug in our DC power supply and start troubleshooting what's going on with the one wire circuit go from there I'm gonna plug in my power supply and let's see what we start drawing we don't have a light and pretty much getting nothing I'm getting 0.013 so that sounds like there's an early short or something stopping really early on in the computer to where it's not getting through the rest of it so let's look at our schematics here and see what could potentially be your issue you so our power is going to come through let's take a look at our three-point RPP 3v4 to underscore g3 hot power supply and see if all that looks normal and our spi ROM is right here the j6 100 and it's very possible something might be messed up around this area so let's check and see if this is even getting turned on in our pin 6 on you 70 90 so we put this underneath our microscope this is going to be our u 70 90 well it's not what we need okay there we go and pin 6 is going to be on the bottom right-hand side of our orientation you take my multimeter and put it into voltage and let's see for getting any power you all right we're getting 18.2 so we are getting power to our chip let's take a look back and see what the rating is supposed to be yeah eighteen point five so we are getting voltage going into our u 7090 this is going to be what creates PP through v4 - so is it putting out power let's check to see if we even have our PP 3v4 - if it's present then we're gonna check out our power rails after that and the board just flipped over on this side let's flip it back over to the orientation we're in so that's going to be this giant capacitor or pin - on you 70-90 so with our multimeter let's probe that area see what we have pintu we're getting exactly 3v4 - so now that we are getting power directly to our pp3 before - then we'll have to check what else is going on so PP 3 V 4 - is going to have to talk to our SMC and our SMC then sends a signal back to our MagSafe oh man I forgot the name of the rail but let's see if we can take a look at it take a step back let's take a look at what the one wire circuit looks like on an older Mac Book Pro unibody and I was actually looking at one earlier today a 2 0 to 9 1 5 this is going to be a 15 inch 2011 MacBook Pro but on the schematics here it actually shows where the sis 1 wire is located so just looking through the table of contents here we've it was still on here I don't think they removed it at the time and I know it's right in my face let's do a search so that's called sis 1 wire I believe it's felt like that it's not spelled like that so sis one wires one wire one word it is alright so on our schematic it does actually show us we're looking at so on our 15-inch MacBook Pro we have our Mac safe one which plugs into the board right here at J 6900 J 6900 sends 18 point 5 volts through at PP 8 18 V 5 DC infuse ghost the refused and then that fuse is going to go to P P DC ng3 hot and if we follow that that is going to go to our pp3 before to regulator you yuria so right here this is going to be pretty much the same chip we're looking at on our MacBook Air we're just referencing an old schematic here and we can see PPD CNG three hot goes through this diode and this diode is responsible for taking power either directly from P P bus which is going to be generated from the battery or from P P DC ng3 hot which is going to be generated from our Mac safe and in this case we only have our Mac's a plugged in so it goes through this diode and eighteen point five volts goes through on this one pin seven then goes through our enable on pin four and then out is going to be P P 3 P 4 2 so we do have that on our J 6900 back to assist one wire and from there we get PP 3 V 4 2 which comes to this logic gate and this logic gate how it works is if both a and B are present on this logic gate you use 6901 then Y will be the result so as long as we have s/m CBC AC okay go to the logic gate then it will send pp3 before - from five it's going to come out of wipe in four becomes smc bc AC okay VCC and that's what powers this chip here use sixty nine hundred and you 6900 then sends a signal to adapter sense an adapter sense is then what turns on the MagSafe charger so we have to apply the same logic to our macbook here and what i'm going to do just to make sure i can i can reference this is I'm going to just open up another flex board view let's go back to our MacBook Air so here we are now and we've already verified that pp 3 before 2 is present so now let's check out to see if we have at SMC bc AC ok let's do a search for that so that is SMC underscore BC underscore AC ok where are you located it looks like it is generated from you 7100 you 7100 is going to be our battery charger or our ISL are in rush limiter which then sends the signal to our SMC so here is you 7100 and pp3 before to g3 hot comes to pin 12 VHS t I'm not sure what that is up to top my head but where is here's essence SMC bc AC okay so that comes from pin 14 on our macbook air let's make sure that is present so this is our battery in rush limiter this is also what creates pipi bus hmm so this is our inertia limiter and we can see that we got pp3 before to underscore g3 hots going into you 70 100 but while we're here let's let's just go ahead and check and see that SMC bc AC ok is present turn on our our supply and so that was pin 14 which is going to be that top left pin and we're getting 3.3 so that is present and we are getting our SM CBC AC okay which is 3.3 volts which means that you 70 100 is turning on so hmm let's reference our other schematic here from the MacBook Pro so at SMC bc AC okay is then going to go through a logic gate right here which then sends SM CBC AC okay VCC to use six nine hundred do we have anything similar to that on our MacBook Air let's follow SMC be CAC okay and see where it goes okay and we know that that goes to our SMC and then it goes through a resistor it's going to be your J 9500 which is going to be the max a port on this MacBook you [Music] you okay so we know that it's sending the signal to our SMC we need to find out if our SMC is even turning on SMC on off L let's see where this takes us you that's just gonna be our debugging but this is what I want to look at here is you 5110 though this is going to be our reset button that actually sends a signal so we want to make sure that SM reset SMC reset L is present and let's see is that anywhere near our jtag connector it is so you 6100 is going to be our jtag connector and if for any reason pen 12 is grounded then it's going to be holding the reset button preventing the SMC from actually powering on this is where all of our corrosion was let's revisit that and measure to see if we are getting any type of signal [Music] you we should be getting something like 3.3 volts you and we're not so this is going to be where our issues located so either this is grounded or our signal the you 5110 what sends the SMC reset was damaged in the process from the corrosion here I'm going to remove my power supply and put my multimeter into continuity mode and see if there's a beep all right so there's no beep so there's no immediate and ground short to ground on our SMC reset this is good this tells us that there is an issue around are you 51 10 I'm going to get one of these cameras right okay here yeah so SMC reset L is missing this is going to be why we are not getting a signal or on our Mac safe charger because our green lights are excuse me our SMC is not turning on so it's not sending a signal back to turn on these adapter sent signal which turns on the green light on the MagSafe 2 so now we got to explore this chip and find out well let's give it a visual inspection and then we'll also check and see is it even being told to turn on so you 51 10 is going to be just right above our Wi-Fi connection you still working on the cameras I'm working on a Macbook here what do you expect to do that you are are you 5100 you don't look necessarily gross you you let's look back at our schematic here so you've see 3100 is going to be powered by P P 3 P 4 to underscore G 3 hot and that goes into pin 1 which if we look is going to be our top LUT let's see if we have any voltage going through so we'll hook back up our power supply and with it connected we'll take our multimeter and we're just going to tap the top left are you being told to turn on you are so we are getting three point four two volts on you 5100 or you 5110 you five one one zero I'm not good at numbers like other technicians are but that's just one of my mini faults so use me so pin one is getting power and we know that pp 3 V 4 to underscore g3 hot is present so we should have it present right here which goes through a resistor a very very low resistor actually says zero resistance and then goes through becomes PP PP 3 B 4 to underscore g3 hot underscore SMC underscore SP v sr what is that supervisor what does that stand for but we should be getting also a voltage of three point or two let's see if we are getting that so that is on pin three so if we look back over here on our board view that's going to be there's a little test point right here so let's probe that test point we are getting power there so that's not our issue and now let's check and see if you 50 100 is acting as a pullet resistor if actually has 100 kilometres so for measuring resistance what we have to do is turn off our power supply we don't want to measure a live system while it still has power on it and then we're going to put our multimeter into continuity mode or I'm sorry into resistance oh where where is excuse me so where is you 50 100 I didn't click on that Oh awesome all right so it's next to our SMC on the other side I got to flip the board over again you and it's just a lot of hair so you 51 or I'm sorry I'm just about enough 50 100 it was going to be this resistor right here so we should be having about a thousand 100 kilohms and with my multimeter I'm getting a resistance of 53 this is more likely our issue here so let's go ahead and replace this and see if we can get the computer to turn on and for that we need our donor board which we conveniently have plenty of donor boards for this model down here so here's a donor board and just to make sure that that is indeed the right resistance I'm going to measure the impedance on our 5100 on this board we should be getting about 100 kilometres that's exactly what I'm getting awesome so this hopefully is our only issue the board's not liquid damage but there is just that tiny tiny little bit of corrosion that was on Jay 6100 which is the SPI JTAG terminal that doesn't need to be there post production it should be removed before it gets shipped out of the factory but the customer did say that they did get a humidifier so it's possible that she had just enough humidity from the humidifier to damage or build up corrosion or on build-up moisture which then went into RJ 6100 which would be really really disappointing if a common house humidifier is what can kill these computers but that's what that's what we deal with here so this is our patient board the board that's being worked on but some flux on it and I'll take our micro tweezers and just touch both ends and pull it off you set that to the side let's get our donor board you you just like with the patient board we're going to use some flux and this is where I like to act fast I'll grab the resistor and then I will grab the other board while I'm still holding the resistor you put it on are you there is our resistor you so let's see if that fixed it set the donor board to the side and let's turn on our power supply and see if we get a green light you you you still nothing and we're still pulling the exact same amount of current so that wasn't our issue so now that we've replaced that but it's still not turning on let's first find out if this is getting all the proper signals to turn on so looking at you 50 100 or you 5110 we saw that our pull-up resistor right here our 5100 was not present so it wasn't sending out our SMC reset l Oh [Music] let's check and see if our smc on/off flow is present okay we're back so SMC on/off low it's going to be pin 7 on our you 5110 do you I thought we were so close I got just a little overzealous there okay sorry had a customer there for a second so we were trying to figure out our SMC on-off flow so basically this is our switch this is what actually turns on so whenever this drops low it is the equivalent of pressing the power button and there is power there so we don't need to drop that low this should be turning on by itself but it's not yet and SMC loc reset low which is going to be on pin six three point four so that seems fine too now let's look and see what is going on with pin eight which is going to be our reference coming out that goes to the SMC all right sorry about that just had to help another customer there for a second so we where we left off is on SMC reset l was not present and because of that our SMC is constantly being held down in the reset position ah the best way Jesse Jones actually did a very good job describing this so just like on the old video game consoles like a Sega Genesis or an Atari there was a reset button and if you held the reset button down and the console would never turn on well SMC reset is held down when the signal is low so it's a very low voltage or no voltage at all so we want some voltage here which will then send a signal to our SMC to turn on but if there is no signal then this is held down this is L it's a reset buttons holding down the SMC it's preventing it from turning on so what we did is we saw that our 5100 which is a pull-up resistor was missing a instead of pull-up resistor it's resistant nonetheless and it's supposed to have a resistance of a hundred kilowatt we were getting about 50 something kill ohms so we went ahead and we replaced that so after doing that it's still not turning on but let's see if SMC reset L is present so that's going to be pin 5 on u 5110 which is our bottom right and then switch back over to our overhead camera and see if that is present take our multimeter put it into voltage and touch the bottom and we're not we're still not getting anything here so if it's not turning on in all the right resources are here did we check to see a P P 3 B 3 s v AV r FS MC is present that was going to be pin 8 s MC reset L is not present in PP e 3 B 3 underscore s v AV r FS MC we're going to check and see if that's present so that's on pin 8 of our u 5110 and are you we are getting three point three so this is present so is this shorted let's turn off our power supply I'm going to put this into resistance instead measure what the resistance to ground is and we're in the mega ohms so that's not the issue but we're not getting a signal coming out is it possible that are you 5110 is bad is there something that I'm missing here before we start blaming the chip here let's check and see on pin 1 of our our 5100 that we replaced are we even getting voltage over there do we have power coming on the right side we do we do have 3.4 what about over here you so power is going there let's check our resistance make sure we didn't do anything stupid so if we touch our probes together yeah we're getting the resistance of zero you you or as resistance go here I'm now starting to get a resistance hmm about fifty again but it's going up to 80 it's it's fluctuating which leads me to believe doesn't lead me to believe it leads me to believe the common denominator between the resistor here both sides are going to go to our u 5110 so oh yea it's jumping all over the place it's very possible our issue is with u 5110 just to make sure i held onto our old resistor I didn't actually throw it away and I was getting a strange reading you you you and one what reading do you give us you okay so our resistor that I thought was bad is actually giving us the proper reading of a hundred ohms so I'm gonna say with that are you 50 110 is bad and it is messing with our resistance we have here and just to show you why I think that is on you 5110 we're checking our 50 100 and our 50 100 on one side which is pin 2 is going to be our reset and the other side is going to be going into our PP 3 V 4 2 then it goes there is other resistor right here yeah I haven't even checked this resistor but what I was thinking is that since this goes through this resistor and then back to pin three and then this on the side goes to pin five maybe our variable here is going to be our youth 5100 but now that I've said it let me look at our our 51 27 which is going to be directly next to our youth 50 110 poor resistor I'm sorry I blamed you we're going to set you aside we'll put you back on your original or on the donor board so if we ever needed in the future we have that at seven o'clock so it's officially closing time let me see if I can finish this up before we get out of here today so this is going to be our our 5127 let's put it into resistance we should be having a resistance of zero that's exactly what we get you're fine I'm gonna replace you you are potentially our issue here or that's we need to remove our Wi-Fi or airport card that's still here if so if this works then that means that the corrosion on our SPI JTAG terminal was enough to send a short back up to our SMC reset component and kill it okay so I've misplaced my tweezers so I'm just going to use these tweezers I got for mobile Centrex they're Cassie tweezers they're larger than my jaco tweezers but they will work for what we're trying to do I really need to get my thought process organized on logic boards first step should always be checking our power rails this one I could just kind of dived into it thinking IO or issues going to be with our PP 3v4 - but turns out it's going to be closer to a different component you so the interesting thing about this logic board too is the customer had gone to an ASP we then quoted her $800 for a board replacement which I find to be fairly high for this board because I've heard Apple as quoted much lower than that I'm not sure if that was their independent pricing or if there was their pricing from Apple so if so then that means Apple has raised their prices on board replacements for these MacBook Airs this MacBook Air in particular the eight to zero zero zero 165 it's either going to be a 13-inch 2015 or a 13-inch 2017 you you now we're going to grab the same component from our donor board here there's $800 for a 15 or a 2015 or 2017 logic board I find that to be just overly outrageous because I've heard board replacements are typically around 90% the price of the computer but in this case it is almost 100% the price of the computer because let's say let's say this is a 2015 I mean you can't buy 2015's anymore but if he did I'd say the computer would probably still be around 500 to $600 I mean this one doesn't have a terabyte solid say even then that's a modular part that shouldn't affect the logic board price you you but even if it was 2017 right before the new iteration of the new MacBooks I mean the highest one was right at $1,000 so they were but they would be right at 80% and if they did $800 for a board replacement but I don't think that's what Apple's charging I think that's what this independent or I shouldn't even say independent because they're an ASB let's wick up the old solder and put some new low melt solder that wick actually has too much solder on it from the last waking and my players are kind my knot pliers but my wire cutters fountain and I was quick to blame someone on that one that that one was me you you you you you now that we have our pads all nice and tinned up with our low melts solder that was my solder that just fell let's go ahead and put the replacement SMC reset IC in place you so we have a whole bunch of solder sticking out we're going to fix that by going with our micro knife attachment to the micro pencil it makes touching up these small points very very simple so out of curiosity before we do anything else I'm going to touch our our 5100 and check and see if we're getting any inconsistency with our our readings so because before we were getting about a solid hundred on our donor board but on our normal board we were getting ratings jumping all over the place and we are getting a solid hundred so let's see if that fixed it you you you let there be light we have a green light we have a fan spin excellent that's a successful border pair we're going to of course give this one a bath and then do a quality control test but this one was really fun to figure out so this one came in from a affirm in a SP or the customer declined getting it repaired at a SP and then came here instead for us to take a look at it so we opened it up in front of her and couldn't find any signs of liquid damage immediately until we put it under her microscope and saw that our SPI connection the J 6100 had a little bit of corrosion on it oh did our TeamViewer just disconnect it is bear with me for one more second how much have you drank have you finished your data raid yet Sam you know that whole bottle is only half of your intake of daily recommended water okay sorry Ida fix our our connecting to our computer here so I don't have a capture card I'm just using a MacBook Pro so what I'm having to do is just a team view onto my main schematic computer here just to double-check or just to show you what I'm seeing so I'm not actually rendering this on my my macbook was my my lovely wife who's feeling sick after donating blood yesterday or two days ago but to get back onto here so just to show you exactly what we noticed what we discovered is J 6100 had some corrosion well we went ahead and we remove J 6100 and we made sure that we were still getting our shorted it's line which was PP through before to underscore G through hot well we know that that needs to be present in order to send a signal to our SMC reset which is you 5110 and you 5110 is then going to send out as some Siri set L which then goes directly to our SMC which then talks back to the adapter sense on our MacBook Air well we did see that you 5110 was getting all the proper power it was getting all the proper enable lines but it was not actually turning on so we looked at our 5100 we thought our 5100 was the issue because when we measured it with our multimeter we were getting a hundred or we were only getting fifty kilohms instead of 100 kilo ohms well we went ahead and we replace it with our known good our 5100 off of our donor board and we were still getting the resistance of 50 kilo ohms so the only other thing we're measuring when we touch pin 1 and pin 2 on our multimeter on our 5100 is going to be if we go back through here it's going to be pin 3 which is our VIN on u 5110 and our pin 5 and so being that all of our power was present but we weren't actually being powered on and we were measuring the resistance between pin 3 and pin 5 rather than and 1 & 2 on our 5100 we were measuring pin 3 in pin 5 on u 5110 we that was enough evidence to know that the corrosion on Jays 6100 was enough to send some power to directly kill ru 5110 which never sends our SMC reset L which never turns on our SMC which never sends a signal back to our adapter sense which then turns back on the light to allow the computer to start charging or just let alone or one wire circuit so that was the quick tail end to why this MacBook wasn't working we went ahead and we've replaced u 5110 the MacBook is working we're just going to give it an ultrasonic cleaning then do a quality control test and send this out the door with the customer oh sorry I normally don't talk that fast but I was trying to sum that up because I basically had to do that twice just now anyways we have a fixed board and that's it for now if you enjoy these videos please let me know in the comments below and I'll see you in the next one thank you

Channel: iRevive

Views: 2,690

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Id: p4pG_giNs4o

Length: 42min 59sec (2579 seconds)

Published: Tue Feb 18 2020