Thank you for the shout out, Well done !!!!!!! The fault now is not the T2 chip its U7800, Pin1 of L7816 should not have 3.3v, U7800 has a load of mosfet inside and I think the mosfet for L7816 is shorted to 3.3v inside the chip, U7800 is a power management chip, U7800 talks to the T2 chip, The slow running is most probable caused by U7800 reporting bad voltages, Get the Coder to swop U7800 from the other board. On another note when removing the ic for 5v and 3.3v rail you can't test for a short because the gates of the mosfets are floating the mosfet could give you a false short on a rail.Great Video 👍👍👍👍I only pointed you in the right direction you solved the fault. 👍👍👍👍👍👍👍👍
It's a pleasure AR...Thank you for helping!!!! I noticed the same 3.3v on L7816 whilst watching back the video before it went live. That should be 0.9V!!! Pin 10 and 28 on the U7800 which feed L7816 are next to pin 11 and 29 which are 3.3v. I thought they might have shorted across and fed 3.3v into that 0.9v line. I wondered whether the T2 had shorted internally as it might have been fed with more than 0.9v when the voltage was fluctuating on PPBUS G3H and the 3.3v rail. I'll ask Cod3r if it is possible to do 324 balls by hand...that will keep him busy for a good couple of hours🤣🤣🤣🤣 I will look into HW Monitor but I don't think I will be able to get into it to download it. This thing takes 15 mins just to open a RUclips vid! I will keep you updated. Thanks again for the help👍👍👍👍👍👍👍👍
The name "BUCK5" seems to indicate a buck converter which would make it a 2-phase buck converter (IE step-down) - the "FB" line is for the feedback (measuring output voltage) which also indicates that it's some kind of voltage supply. Without checking the rest of the schematics the name PP0V9_SLPDDR would indicate that it's a 0.9V rail for the LPDDR(4?) memory, and the notes around it says 0.9V/2.64A (max) at 3.0MHz switching frequency. Having two phases reduces ripple but if it really runs at 3MHz that's a *really* high switching speed for an SMPS which means the ripple should be rather small even with one phase, frequencies like that are only doable on integrated SMPS chip with built-in MOSFETs like this appears to be. Putting the inductor into the chip is hard, so I'm not surprised to see one external inductor per phase, connected to one (or more) capacitors per rail (voltage). As a comparison a modern desktop motherboard (or GPU) runs it's various VRMs at usually 150-400 kHz (and you'll never see anyone go above 500kHz even at the extreme end) and most of the time the only rail that isn't single-phase is the main CPU power rail. There are motherboards with two phase memory power but they're rare even among expensive motherboards, DDR4/5 draws a lot more power than LPDDR but it's still not enough that more than one phase is really necessary even at "mere" 150-400kHz. You need to consult the data-sheet for that chip to be sure (if you can find it) if the second phase is necessary for the specified current - they EITHER did that because the inductor was cheaper than increasing the capacitance (the other way to reduce ripple) OR because the internal MOSFETs are really weak. I don't think it's the T2 chip that's faulty since the machine runs (somewhat) on that single phase, and everything else is connected in parallel from that rail, yet it only fails if that SW0 line is connected. To my mind this pretty much proves it's internal to that U7800 SMPS chip or underneath it!. If forced to guess it would be that the transistors driving the P0V9SLPDDR_SW0 inductor failed since they can fail with resistance like that AFAIK I'm not good enough at buck converter design to say if it's the low or high-side MOSFET that died though "to ground" kind of smell low-side to me (but as mentioned, definitely not an expert). As to why it failed in the first place, could have been any kind of reason including but definitely not limited to water damage (shorting out the output can easily blow up a MOSFET). With regards to why it's now so slow, my guess would be that the motherboard firmware detecs the some kind of issue and goes into some kind of "limp home" mode. It might not even be the SLPDDR rail that causes the slow-down, if it was water that got under the SMPS chip there might be additional phases that failed in different modes where the chip was able to disconnect them but the motherboard firmware knows it can't draw substantial power - I know some SMPS controller that drive external MOSFETs have features like that (bypassing failed phases!). If say one or more of the main CPU power phases has also failed it would need to either not start or downclock the CPU to the point that it won't draw large amounts of power. Speculation: IIRC these Apple laptops use disk encryption that can only be read with at least some of the chips working - even moving or accessing the soldered flash memory directly won't help retrieve the data, you need at least the T2 chip running? And AFAIK Apple service shops have special tools that can often but not always copy the data even if the laptop isn't working enough to be able to boot OSX, so perhaps it part of that? Limiting damage and allow you to go to an Apple service center and move the data to new Apple laptop?
Interesting part with the "limp home" mode. Sounds very possible and almost simillar like modern car engines. When sensors detect that there is some kind of malfunction with the engine, it goes into this safe mode where engine still works but maybe around 1/5 of its power, allowing you to at least finish your trip or drive to nearest repair shop.
Vince, if the fan is running all the time then the machine is seeing it’s thermal sensors saying it is too hot so throttle back performance. There should be an istat utility to display what the sensors are seeing and give you a clue what is going on now that you have it booting. Well done ... don’t give up! 👍😀
@@Mymatevince vince, it’s the battery!!! Replace it and it will go straight back to normal, have this issue pop up constantly on MacBooks that have been sitting for months. The batteries completely die and cause this funny issue!!!
@@LucasLane I have a Toshiba laptop a few years old, was Windows 7 and upgraded to Windows 10 and was running very slow so I took out the dead battery and viola! Runs like new!
Been watching these videos for long. Nothing better than to hear that happines! Fantastic. Doesn't matter what hardware really. But computers and old video games is my favorite.
@39:24 That emotional moment that we all crave - congratulations; was fantastic to watch you work your way through the process. Yes, with regards to the multiphase power output, we do at times pull phases off just like you did to see if we can isolate a bad one, often with CPU or GPU rails; though of course we do like to get them all back up and running in the end. Are you going to try replacing U7800? It isn't too bad - it's a bit like an early iPhone CPU, and you can use an iPhone stencil to do the reballing. Thank you for the entertaining video; the excitement and "shakes" were palpable :D (PS, sent an email with some more details)
I’m getting Louis Rossmann vibes here. As far as I’m concerned about it being slow and the fan constantly running at full speed: it might be a bad temperature sensor. My suggestion is to get the app Macs Fan Control and check if all the sensor values shown there make all sense. But you did an amazing job, Vince!!
The 2020 model (core i3) only has a tiny little heatsink to cool it self down the fan doesn’t do anything thats why its on 24/7 this was proved in a linustechtips video as he showed the fact 5hat it would nearly always hit 80 Celsius even when just sitting on a flat surface and not doing anything it doesn’t have anything to do with the temperature sensor i will send the video as a link to help you further understand what i am saying here.
Could be, ie, if it's thinks it's hot it probably throttles. On Tech Cemetery he has GPUs that run, but because of some other fault they don't run at full clock. Benchmark apps show it, but Mac probably doesn't have any.
honestly the fact the fans are constantly ramping up and it being slow can be a sign of a failing SMC or PMU chip. I have a 2009 MacBook with a failing SMC chip and it won’t charge a battery, it’s a little slow and the fans are constantly at full blast
I have had similar experiences when trying to repair a much older (circa 2010) MacBook Air and MacBook Pro. They took ages to do anything and the fans were on all the time. With the MacBook Air, it was because I had installed the wrong battery (one intended for the previous model year, I believe). Replacing the battery fixed the issue. The MacBook Pro had a faulty temperature sensor in the trackpad, which I replaced, although that one was still a bit unreliable since I think it also had water damage. The point is that sometimes weird things can cause the system to run very slow (and also with the fans going 100%). It's possible that it's not even related to the chips.
Hey Vince, great video as always. I had a 2018 Macbook Air that had exactly all the same issues as yours (Slow startup, fans at full speed, excruciatingly slow performance). I also noticed that when you clicked on the battery icon, it said that it needed service and it also was not charging. After doing lots of research on my Macbook's problems, discarding thermal sensors and whatnot, i concluded that the battery was faulty, and i read lots of posts saying that Macbooks throttle like this when the battery is either dead, or not working properly. My Macbook was fixed by replacing it's battery, i suggest you try that too, it is a very simple process and you can get one for around $60-$70. As i said earlier, love your videos, keep up the great work, greetings from Argentina. Cheers!
Fantastic lol! This has to be one of your best videos =D Your reaction was just brilliant! The speed problem - is it perhaps related to the fact that one of those 2 switched rails is missing? My other thoughts - if its not charging either, maybe one or both of those issues related to power management - ie. it's slowing CPU clock down because it thinks the battery is low or something?!?!
That clock speed on the cpu is low is because the fact that apple didn’t actually decide to have the fan exhaust the hot air from the cpu which explains it all The macbook he is fixing is not good for doing much because of the cooling system that apple implemented inside it so its better off to be sold than him give it to his daughter as he said in the last video but its still interesting and dun to watch him fix it even though i have no knowledge of electronics at all eventually i will as i get older but for now all ill say is that the macbook is the worst macbook apple ever released (core i3) and a tiny heatsink If this didn’t make sense then after i watch the video i will edit it as i know the reason behind the underclocking
Thank you Chris, the battery is super low 4.6V. I just changed the battery out from the rose gold one which is low but 6V. It is still not charging and still full fan speed and awful performance. I'm leaving it off and charging to see if the voltage increases but right now after 30 minutes it is charging at 20V but only 0.03A, so I don't think it is registering a charge at all. Some have mentioned a faulty sensor which I need to look into 👍👍👍👍
@@Mymatevince What I mean is maybe the "sense" circuit or feedback circuit is borked. Perhaps a fault related to power management. If it thinks its running on battery (which is low) it will limp at a really low clock speed. Someone pointed out it is a Core i3 which is pretty low spec, so maybe that's the issue. Can you get into the performance "thing" in Mac OS and see what its reporting regards clock speed and how much RAM is there?
Excellent video Vince! I love your reactions when things suddenly work out. They are so honest, and heartfelt that I catch myself doing the same on your behalf. I'm so impressed by your progress! The fact that you don't give away the ending is a good thing in my book, as failure in spite of great effort is just the way it is sometimes. I can however empathize with the people that sit through 50 minutes of fixing, and then it doesn't work after all. "Good judgment comes from experience; experience comes from bad judgment" - Dr Kerr L White
Load activity monitor and check to see kernal usage. If kernal is running at like 95% that's a good sign the cpu is being throttled. I'd suggest first off boot into safe mode and see if you get the same results Then if so try swapping the battery over as a duff or hot battery can often nuke cpu performance
Awesome getting this to boot Mr. MACBOOMINATOR. Loved the emotion you went through. I will say though that it seems you do have either a sensor or a ram issue. I'd love to give this a crack if you dared to let me near it? 😂
Thanks Phil, you may well have 324 balls to hand reball if you are not careful 🤣🤣🤣 It looks like it is the U7800 chip at fault and it needs swapping with the rose gold liquid damaged MacBook. I want to check this sensor issue out first AND I was tempted to put 0.9V from my bench power supply into that missing rail to see if it speeds things up????? Do you think that would be a foolish idea to force 0.9v at a low amperage in to see what happens????? At least that can kick start my Mr. MacBOOMinator name off 🤣👍
@@Mymatevince haha only 324? I guess you've not seen the hand reballs of PS4 APUs then? 😂 in all seriousness I'd be happy to try for you if you run out of options. To be honest what I was thinking is that if your 3.3v rail had a direct short to the 0.9v rail it stands a chance the ram could be a goner. It would be a bit more interesting if I had to replace the ram for you though 😂 that said I don't think injecting 0.9v into the 0.9v line would harm anything. One tip I could give is if you're for example thinking of injecting voltage just check for a direct short to the lower rails first. If there's no short to for example the 0.9v, 1.1v, 1.8v and 2.5v lines you can safely go all the way to 3.3v 😁 Looking forward to video #3 now though. Hopefully you fix it, but if not I don't mind taking a crack at it just for fun 😁
@@Mymatevince i would try another battery if possible its a known issue with most macbooks that if the battery is left fully depleted for a few months it can cause the system to go in to limp home mode because the sensor thats inside the battery thinks its bad
If the CPU is getting too hot, which would be why the fans are running full speed, then it will be thermal throttling. You might want to check if the CPU cooling is correctly installed.
i would try raplacing the battery to see if the speed gets better. Alternativly there could be somekind of a sensor (thermal? )issue and thus the fan is at full speed and cpu slowing doen. Also i think Luis Rossmann said something about current sensing issue causing fan speed to ramp up
@@LucasLane He has a gold macbook of the same vintage, which probably has a good battery - I'd swap the board into that one and see if it works any better (sure the gold one is water damages, just don't connect the trackpad or keyboard, and use external ones, hopefully the screen connector and wifi antenna's are fine). If that improves it he can go to the trouble of acholing out the battery pack from the gold one and transplanting it into the space grey one.
Useful schematic reading tips: 2k2Ω means 2.2K or 2200 Ohms. 4R7 means 4.7ohms, 3V3 means 3.3 Volts, so P3V3G3H is Power 3.3 volts G3H. 1V8 would be 1.8V P5V should be power 5 volts. The different letters and numbers before and after its to differentiate regulated or unregulated voltages and rails before and after a fuse or a diode that would break the rail in two parts (before and after the fuse its two different rails (nets) on the PCB design software.)
Hi Vince... the TPS51980 is a buck converter. SW0 and SW1 are switcher outputs. My guess i that they use two switcher outputs for current. With only one switcher rail working, you are current limiting the cpu. Change the TPS51980. Cup of tea says it works.......
I had a moment of joy like this a few month back when I fixed a faulty vcr)/dvd combi from ebay, it had various faults, and kept blowing components in the power supply, and even when I eventually fixed the power supply, a ribbon that must have been put in the wrong way round years ago(and matched the others around it so it looked normal) had actually been installed the wrong way round meaning the dvd part didn't work, found it eventually with a schematic. When It was all fully working again I felt such a relief and joy, it's hard to describe
I would change the other chip not the T2 one, can be that one of the internal MOS that drive the gate output went bad. Normal as you said when you have high res it's always something bad in the silicon. I know it's another BGA but it has way less ball than the T2 chip!
Hey vince, I found faulty battery’s cause this exact issue. Try a new battery, the only thing I’ve found that fixes this issue. Please guys like this so he can see, I’ve had this issue countless times and a new battery always fixes it!!
I highly suggest to look around why it is not charging. I had similar slow response when my surface pro 4 battery was dead completely and only was working from the charger. It just slowed down the CPU to not overload the charger, because it needed more current, but was not able to supply without battery.
Yeah, I agree with other users that it's an issue with the battery, though I'm unsure if the battery is serialised and locked in like on a number of iPhone models. The battery probably was left discharged for so long that the battery controller likely fell into an error state, well, at least I've seen that happen with some PC laptops. I'm also glad the previous owner remembered to disable tracking (which when left enabled prevents Apple platform initial setup from proceeding).
Can’t believe you got it going, amazing, well done! You mentioned a couple of times in the video that you wondered why the short resistance was less when the temperature went up. That’s true for any semi-conductor, which is different from a metal, where the resistance goes up with temperature. That helps you narrow it down to a semi-conductor component on the board!
Well done Vince, i'm sure you will get it fixed with the help of people in the comments! I recently had an old macbook air which had a drink of tea through the keyboard, it would boot eventually but was running slow. After replacing the keyboard it was fixed, also battery was dead but it seemed to recover after fitting keyboard. Good luck, Allan
I work in IT, you find the dumbest overlooked "well DUh" stuff when you follow the process.....some ppl get lucky and can figure out where to start the process, but you still need the process. Otherwise it's guesswork. Most people can't figure where to start, thats why I watch the video's, even if it doesn't completely relate to what I'm looking for, it's still good practice to know at least a little bit.
Vince, I love the Way you work on these Items. And well done! maybe TheCod3r can replace the DDR feeding chip with the one on the other donor board, you have at the beginning. and he may also be able to reball the T2. It's worth a try, isn't it? And even if not, keep your happy mood :) that cheers me up every time.
Vince I've been watching your channel since you had at least under a hundred subscribers and I love your content so sorry you couldn't get the MacBook working correctly
Try using the dead one's battery. Or, like I just read, check the thermal sensors, maybe they are faulty so the Mac think it's too hot to work normally. Nice videos, greetings from Argentina, I have learnt a lot watching you repair stuff.
That jingle never gets old. Litterally sometimes like now me watching this video. I ended up playing the jingle twice. Yes I know some people might say that. That is a bit obbsessive, but come on, you've got to admit it. That is a pretty great catchy jingle. Great job Taz Cat.
Hahaha, I love it, it is too long to play on each video but I've listened to it dozens of times so I'm with you. If 2 of us think it then it must be good!!! 🤣🤣🤣
Amazing video Vince! And you reaction was priceless and I slammed my table too at that very moment. :D With that said, I looked through some of the comments and I think the T2 chip is fine. I think the power management chip is the one at fault (it did get hot also on applying voltage). I think you can swap out the chip from the other board you have got. I know you said there might not be a revisit with this again but I sure look forward to one. :)
Thanks Arijit, yes it looks like you are correct, I now know the battery is the cause of the slowness, but it is the power management chip at fault on that fluctuating voltage. Cheers 👍👍👍👍
Thump reaction 10/10! Lol. I know that feeling so well. Watching your videos, you seem to have progressed from simple switch fixes to very complicated micro electronic fixes , and each one is still fascinating to watch. Anyway , I'm off to bash a broken rtx3090 with a lump hammer....keep up the interesting videos please👍
I just bought a similar model in broken condition for really cheap (13" MacBook Air M1, A2337). I don't know the specs and it somehow was broken in half. I'm really looking forward for this fix as it will be the newest MacBook I ever tried to fix. I hope I "just" need a new screen as the bottom part looks fine and not damaged and makes the boot sounds when plugged in.
Swap the battery! CPU throttles down with a defective battery like this.. I had the same issue is a 2011 MacBook Pro 13'', added a new battery and worked like a new laptop.
My experience troubleshooting Mac are only replacing pieces, I dont know if what i'm saying below is something technically right, thats just my experience using e troubleshooting my own MacBook Air 2012...... Apple's Macbook seems to have some problems when the battery was fully discharged.... For exemple, my Macbook when i needed to replace the battery was impossible to use, because these latency problems... I recomend you to fully recharge it, than reset it one or two times, sometimes it worked for me.... I think its their bios config, when have some problem with the energy supply they force the Mac to run slowly to avoid bigger problems...
Hey Vince, I'm just thinking that another pair of spare multimeter probes with sewing pins soldered to each tips might help while probing around tiny tiny pads.Nice video, handsome.
As others have said, you have a sensor problem. It has several sensors mounted in different places. On earlier models, there was one mounted on the DC IN board and another in the keyboard/palm rest area. You can find software to help you narrow down which one is the problem.
I had the same problem where in the task manager the kernel task took up most if the cpu usage making it unbearably slow. Fans were also at full speed. Guy that fixed the motherboard said it was one of the chips that manages the temperature as it panics
I did wonder about the battery as well and noticed when you clicked up there it seems to show an error service was needed or something? I was working on an older Macbook Pro which worked perfectly it was just super, super slow and found a faulty battery can cause this, I swapped it over and the problem immediately disappeared. However the fan behaviour was normal and I wouldn't think a 2020 model would have a dud battery so i could be a faulty temperature sensor which was the other suggestion.
great video! Very interesting and entertaining. And with all the great ideas in the comments, I think it is worth to do a second revisit video. I would love to see that.
I don't know if this was pointed out, but a bad battery will also greatly affect performance same as the way your Macbook behaves. Maybe swap it out and try booting again to compare? Good luck
Something you can try is a SMC reset and a PRAM reset and see if that makes it faster, as sometimes when they get confused it makes the machine run really slow.
Vince, change the battery and see what happens. When a Mac's battery goes completely flat and you try to charge it, the system kicks into a type of protection mode. Maybe you'll get lucky and that's all it is. I personally seen three MacBooks do this and it was the battery.
Come on Vince, you can't give up... you're like centimeters from success. I'd revisit the battery (without a properly working battery, macs like to behave erratically) and also check sensors because the fan should definitely not be running constantly. If it is running constantly, it means that either the cpu (or something else) is constantly throttling or that one (or more) sensor can't be read or is showing something silly. I'd sort these out first and worst case, bring it somewhere to exchange the T2 chip on your boards (if that can be done, because you might loose the contents of the storage if it is tied to the T2, I'm not sure about that though... check with someone more knowledgeable about newer machines... my limited competence ends around 2012 models or so :D).
Nice work on getting it booting at least! With regards to the horrible performance, a similar thing happened to me a while back. I was attempting to change the battery on my older MacBook Pro. While doing so, I accidentally ripped off the cable connecting the webcam to the motherboard. I was gutted, but figured I could do without the webcam. Turns out, the cable getting ripped off also broke a temperature sensor on the board. As a result, MacOS couldn't get a temp reading and put the machine in a state where it assumed it was overheating. Hence, the fans were running at full blast, and the CPU was being VERY aggressively underclocked to the point where it was barely functional. Virtually identical to the problem you're having. Thought I'd share that anecdote, perhaps something similar is happening on your machine?
Some other people may have ruled this out, and I don’t know whether this affects the newer MacBooks, since I see a lot of comments saying a CPU issue, but honestly I think it’s an SMC fault, or well, a failure that hasn’t quite happened yet, I have a 2009 MacBook Polycarbonate with a dying SMC so you have to do an SMC bypass whenever it boots up and the fans are constantly running at full and it’s slow, and will refuse to charge a battery or pretend it’s not there.
Thank you for the shout out, Well done !!!!!!! The fault now is not the T2 chip its U7800, Pin1 of L7816 should not have 3.3v, U7800 has a load of mosfet inside and I think the mosfet for L7816 is shorted to 3.3v inside the chip, U7800 is a power management chip, U7800 talks to the T2 chip, The slow running is most probable caused by U7800 reporting bad voltages, Get the Coder to swop U7800 from the other board. On another note when removing the ic for 5v and 3.3v rail you can't test for a short because the gates of the mosfets are floating the mosfet could give you a false short on a rail.Great Video 👍👍👍👍I only pointed you in the right direction you solved the fault. 👍👍👍👍👍👍👍👍
Try running HWMonitor (Mac) and see if all the sensors are reading correctly
It's a pleasure AR...Thank you for helping!!!! I noticed the same 3.3v on L7816 whilst watching back the video before it went live. That should be 0.9V!!! Pin 10 and 28 on the U7800 which feed L7816 are next to pin 11 and 29 which are 3.3v. I thought they might have shorted across and fed 3.3v into that 0.9v line. I wondered whether the T2 had shorted internally as it might have been fed with more than 0.9v when the voltage was fluctuating on PPBUS G3H and the 3.3v rail. I'll ask Cod3r if it is possible to do 324 balls by hand...that will keep him busy for a good couple of hours🤣🤣🤣🤣
I will look into HW Monitor but I don't think I will be able to get into it to download it. This thing takes 15 mins just to open a RUclips vid!
I will keep you updated. Thanks again for the help👍👍👍👍👍👍👍👍
@@Mymatevince Anytime , lets hope for the best. I am sure Cod3r will enjoy doing 324 balls 🤣
@@AnonymousRepair saw a girl do it on porn hub, So it’s doable. Wait, what were you talking about?
@@AnonymousRepair 🤣🤣🤣
The name "BUCK5" seems to indicate a buck converter which would make it a 2-phase buck converter (IE step-down) - the "FB" line is for the feedback (measuring output voltage) which also indicates that it's some kind of voltage supply. Without checking the rest of the schematics the name PP0V9_SLPDDR would indicate that it's a 0.9V rail for the LPDDR(4?) memory, and the notes around it says 0.9V/2.64A (max) at 3.0MHz switching frequency.
Having two phases reduces ripple but if it really runs at 3MHz that's a *really* high switching speed for an SMPS which means the ripple should be rather small even with one phase, frequencies like that are only doable on integrated SMPS chip with built-in MOSFETs like this appears to be. Putting the inductor into the chip is hard, so I'm not surprised to see one external inductor per phase, connected to one (or more) capacitors per rail (voltage).
As a comparison a modern desktop motherboard (or GPU) runs it's various VRMs at usually 150-400 kHz (and you'll never see anyone go above 500kHz even at the extreme end) and most of the time the only rail that isn't single-phase is the main CPU power rail. There are motherboards with two phase memory power but they're rare even among expensive motherboards, DDR4/5 draws a lot more power than LPDDR but it's still not enough that more than one phase is really necessary even at "mere" 150-400kHz.
You need to consult the data-sheet for that chip to be sure (if you can find it) if the second phase is necessary for the specified current - they EITHER did that because the inductor was cheaper than increasing the capacitance (the other way to reduce ripple) OR because the internal MOSFETs are really weak.
I don't think it's the T2 chip that's faulty since the machine runs (somewhat) on that single phase, and everything else is connected in parallel from that rail, yet it only fails if that SW0 line is connected. To my mind this pretty much proves it's internal to that U7800 SMPS chip or underneath it!. If forced to guess it would be that the transistors driving the P0V9SLPDDR_SW0 inductor failed since they can fail with resistance like that AFAIK I'm not good enough at buck converter design to say if it's the low or high-side MOSFET that died though "to ground" kind of smell low-side to me (but as mentioned, definitely not an expert).
As to why it failed in the first place, could have been any kind of reason including but definitely not limited to water damage (shorting out the output can easily blow up a MOSFET).
With regards to why it's now so slow, my guess would be that the motherboard firmware detecs the some kind of issue and goes into some kind of "limp home" mode.
It might not even be the SLPDDR rail that causes the slow-down, if it was water that got under the SMPS chip there might be additional phases that failed in different modes where the chip was able to disconnect them but the motherboard firmware knows it can't draw substantial power - I know some SMPS controller that drive external MOSFETs have features like that (bypassing failed phases!). If say one or more of the main CPU power phases has also failed it would need to either not start or downclock the CPU to the point that it won't draw large amounts of power.
Speculation: IIRC these Apple laptops use disk encryption that can only be read with at least some of the chips working - even moving or accessing the soldered flash memory directly won't help retrieve the data, you need at least the T2 chip running? And AFAIK Apple service shops have special tools that can often but not always copy the data even if the laptop isn't working enough to be able to boot OSX, so perhaps it part of that? Limiting damage and allow you to go to an Apple service center and move the data to new Apple laptop?
Thanks Torbjorn for the detailed, interesting info👍👍👍👍
what he said lol ☝☝☝☝
Thumbs up for this message. No idea what you're talking about but you're definitely know your stuff lol
Exactly my thought, Vince try to change the U7800 chip over from the water damaged board and put the inductor back.
Interesting part with the "limp home" mode. Sounds very possible and almost simillar like modern car engines. When sensors detect that there is some kind of malfunction with the engine, it goes into this safe mode where engine still works but maybe around 1/5 of its power, allowing you to at least finish your trip or drive to nearest repair shop.
Vince, if the fan is running all the time then the machine is seeing it’s thermal sensors saying it is too hot so throttle back performance. There should be an istat utility to display what the sensors are seeing and give you a clue what is going on now that you have it booting. Well done ... don’t give up! 👍😀
Thank you Chris, I will look into the sensors 👍👍👍😁
@@Mymatevince vince, it’s the battery!!! Replace it and it will go straight back to normal, have this issue pop up constantly on MacBooks that have been sitting for months. The batteries completely die and cause this funny issue!!!
@@Mymatevince the issue happens because the laptop doesn’t want to overload the charger. It throttles the whole machine so it doesn’t shut down!
@@LucasLane I have a Toshiba laptop a few years old, was Windows 7 and upgraded to Windows 10 and was running very slow so I took out the dead battery and viola! Runs like new!
@@LucasLane maybe he could try to use the battery from the rose gold one
Never heard Louis Rossman cry of pure joy. Well done!
CPU throttles down with a defective battery like this, try swapping the battery
Been watching these videos for long. Nothing better than to hear that happines! Fantastic. Doesn't matter what hardware really. But computers and old video games is my favorite.
@39:24 That emotional moment that we all crave - congratulations; was fantastic to watch you work your way through the process.
Yes, with regards to the multiphase power output, we do at times pull phases off just like you did to see if we can isolate a bad one, often with CPU or GPU rails; though of course we do like to get them all back up and running in the end. Are you going to try replacing U7800? It isn't too bad - it's a bit like an early iPhone CPU, and you can use an iPhone stencil to do the reballing.
Thank you for the entertaining video; the excitement and "shakes" were palpable :D
(PS, sent an email with some more details)
Hole world are watching - a power of Internet people united don't need a government
@@AV-hx1bm Viva la revolution 😜
@@MrPnew1 i dont See one xD
Thank you Paul...A true master of MacBooks!!! 😁
@@Mymatevince oh still very much early days with the repairs. Thank goodness for signature faults!
I’m getting Louis Rossmann vibes here.
As far as I’m concerned about it being slow and the fan constantly running at full speed: it might be a bad temperature sensor. My suggestion is to get the app Macs Fan Control and check if all the sensor values shown there make all sense.
But you did an amazing job, Vince!!
The 2020 model (core i3) only has a tiny little heatsink to cool it self down the fan doesn’t do anything thats why its on 24/7 this was proved in a linustechtips video as he showed the fact 5hat it would nearly always hit 80 Celsius even when just sitting on a flat surface and not doing anything it doesn’t have anything to do with the temperature sensor i will send the video as a link to help you further understand what i am saying here.
Could be, ie, if it's thinks it's hot it probably throttles. On Tech Cemetery he has GPUs that run, but because of some other fault they don't run at full clock. Benchmark apps show it, but Mac probably doesn't have any.
honestly the fact the fans are constantly ramping up and it being slow can be a sign of a failing SMC or PMU chip.
I have a 2009 MacBook with a failing SMC chip and it won’t charge a battery, it’s a little slow and the fans are constantly at full blast
My Mate VINCE is now the replacement for Louis Rossmann because he is too busy making political videos now.
I was joking in my comment, I have been watching Vince for a while and I know he does a LOT more than repair MacBooks
I have had similar experiences when trying to repair a much older (circa 2010) MacBook Air and MacBook Pro. They took ages to do anything and the fans were on all the time. With the MacBook Air, it was because I had installed the wrong battery (one intended for the previous model year, I believe). Replacing the battery fixed the issue. The MacBook Pro had a faulty temperature sensor in the trackpad, which I replaced, although that one was still a bit unreliable since I think it also had water damage. The point is that sometimes weird things can cause the system to run very slow (and also with the fans going 100%). It's possible that it's not even related to the chips.
Hey Vince, great video as always. I had a 2018 Macbook Air that had exactly all the same issues as yours (Slow startup, fans at full speed, excruciatingly slow performance). I also noticed that when you clicked on the battery icon, it said that it needed service and it also was not charging. After doing lots of research on my Macbook's problems, discarding thermal sensors and whatnot, i concluded that the battery was faulty, and i read lots of posts saying that Macbooks throttle like this when the battery is either dead, or not working properly. My Macbook was fixed by replacing it's battery, i suggest you try that too, it is a very simple process and you can get one for around $60-$70.
As i said earlier, love your videos, keep up the great work, greetings from Argentina. Cheers!
Fantastic lol! This has to be one of your best videos =D Your reaction was just brilliant! The speed problem - is it perhaps related to the fact that one of those 2 switched rails is missing? My other thoughts - if its not charging either, maybe one or both of those issues related to power management - ie. it's slowing CPU clock down because it thinks the battery is low or something?!?!
That clock speed on the cpu is low is because the fact that apple didn’t actually decide to have the fan exhaust the hot air from the cpu which explains it all
The macbook he is fixing is not good for doing much because of the cooling system that apple implemented inside it so its better off to be sold than him give it to his daughter as he said in the last video but its still interesting and dun to watch him fix it even though i have no knowledge of electronics at all eventually i will as i get older but for now all ill say is that the macbook is the worst macbook apple ever released (core i3) and a tiny heatsink
If this didn’t make sense then after i watch the video i will edit it as i know the reason behind the underclocking
@@WM22 Ah, I didn't know it was a Core i3! That's not going to help for sure!
Thank you Chris, the battery is super low 4.6V. I just changed the battery out from the rose gold one which is low but 6V. It is still not charging and still full fan speed and awful performance. I'm leaving it off and charging to see if the voltage increases but right now after 30 minutes it is charging at 20V but only 0.03A, so I don't think it is registering a charge at all. Some have mentioned a faulty sensor which I need to look into 👍👍👍👍
@@Mymatevince What I mean is maybe the "sense" circuit or feedback circuit is borked. Perhaps a fault related to power management. If it thinks its running on battery (which is low) it will limp at a really low clock speed. Someone pointed out it is a Core i3 which is pretty low spec, so maybe that's the issue. Can you get into the performance "thing" in Mac OS and see what its reporting regards clock speed and how much RAM is there?
@@GadgetUK164 There will be a re-revisit Chris!!!🤣🤣🤣
Excellent video Vince! I love your reactions when things suddenly work out. They are so honest, and heartfelt that I catch myself doing the same on your behalf. I'm so impressed by your progress!
The fact that you don't give away the ending is a good thing in my book, as failure in spite of great effort is just the way it is sometimes. I can however empathize with the people that sit through 50 minutes of fixing, and then it doesn't work after all.
"Good judgment comes from experience; experience comes from bad judgment"
- Dr Kerr L White
Load activity monitor and check to see kernal usage. If kernal is running at like 95% that's a good sign the cpu is being throttled.
I'd suggest first off boot into safe mode and see if you get the same results
Then if so try swapping the battery over as a duff or hot battery can often nuke cpu performance
Awesome getting this to boot Mr. MACBOOMINATOR. Loved the emotion you went through.
I will say though that it seems you do have either a sensor or a ram issue. I'd love to give this a crack if you dared to let me near it? 😂
Thanks Phil, you may well have 324 balls to hand reball if you are not careful 🤣🤣🤣 It looks like it is the U7800 chip at fault and it needs swapping with the rose gold liquid damaged MacBook. I want to check this sensor issue out first AND I was tempted to put 0.9V from my bench power supply into that missing rail to see if it speeds things up????? Do you think that would be a foolish idea to force 0.9v at a low amperage in to see what happens????? At least that can kick start my Mr. MacBOOMinator name off 🤣👍
@@Mymatevince haha only 324? I guess you've not seen the hand reballs of PS4 APUs then? 😂 in all seriousness I'd be happy to try for you if you run out of options.
To be honest what I was thinking is that if your 3.3v rail had a direct short to the 0.9v rail it stands a chance the ram could be a goner. It would be a bit more interesting if I had to replace the ram for you though 😂 that said I don't think injecting 0.9v into the 0.9v line would harm anything.
One tip I could give is if you're for example thinking of injecting voltage just check for a direct short to the lower rails first. If there's no short to for example the 0.9v, 1.1v, 1.8v and 2.5v lines you can safely go all the way to 3.3v 😁
Looking forward to video #3 now though. Hopefully you fix it, but if not I don't mind taking a crack at it just for fun 😁
@@TheCod3r Good man Cod3r, I'll keep you informed 👍👍👍👍
@@Mymatevince i would try another battery if possible its a known issue with most macbooks that if the battery is left fully depleted for a few months it can cause the system to go in to limp home mode because the sensor thats inside the battery thinks its bad
Could the CPU be in "limp home mode" due to it reporting as too hot? hence the fan?
It's in limp mode due battery being bad. But addition to that it might be also exactly what you said.
If the CPU is getting too hot, which would be why the fans are running full speed, then it will be thermal throttling. You might want to check if the CPU cooling is correctly installed.
Surely it wouldn’t throttle THAT much
I’m sure it’s the temperature sensors
His reaction is priceless, such a brilliant reaction, the joy, the excitement. Wow! ❤
i would try raplacing the battery to see if the speed gets better. Alternativly there could be somekind of a sensor (thermal? )issue and thus the fan is at full speed and cpu slowing doen. Also i think Luis Rossmann said something about current sensing issue causing fan speed to ramp up
This!! The battery is the big culprit here!
@@LucasLane He has a gold macbook of the same vintage, which probably has a good battery - I'd swap the board into that one and see if it works any better (sure the gold one is water damages, just don't connect the trackpad or keyboard, and use external ones, hopefully the screen connector and wifi antenna's are fine). If that improves it he can go to the trouble of acholing out the battery pack from the gold one and transplanting it into the space grey one.
Vince replied to a comment saying he replaced the battery, and it didn't fix it.
Useful schematic reading tips:
2k2Ω means 2.2K or 2200 Ohms.
4R7 means 4.7ohms,
3V3 means 3.3 Volts, so P3V3G3H is Power 3.3 volts G3H.
1V8 would be 1.8V
P5V should be power 5 volts.
The different letters and numbers before and after its to differentiate regulated or unregulated voltages and rails before and after a fuse or a diode that would break the rail in two parts (before and after the fuse its two different rails (nets) on the PCB design software.)
Thank you Thomas 👍👍👍
sensor issue, install a temperature monitoring software and narrow down the sensor that is causing the fault
Another fantastic effort Vince. We're definitely gonna nail this one in part 3!
Hi Vince... the TPS51980 is a buck converter. SW0 and SW1 are switcher outputs. My guess i that they use two switcher outputs for current. With only one switcher rail working, you are current limiting the cpu. Change the TPS51980. Cup of tea says it works.......
yep 0.9v upto 2.6amps for that rail, 1 coil most likely not enough.
The shear woot of your victory made this video worth every second. Thanks for taking us along.
Me: I would like to see a new trying to fix video...
Vince: There you have it!
I had a moment of joy like this a few month back when I fixed a faulty vcr)/dvd combi from ebay, it had various faults, and kept blowing components in the power supply, and even when I eventually fixed the power supply, a ribbon that must have been put in the wrong way round years ago(and matched the others around it so it looked normal) had actually been installed the wrong way round meaning the dvd part didn't work, found it eventually with a schematic. When It was all fully working again I felt such a relief and joy, it's hard to describe
I would change the other chip not the T2 one, can be that one of the internal MOS that drive the gate output went bad. Normal as you said when you have high res it's always something bad in the silicon. I know it's another BGA but it has way less ball than the T2 chip!
Very true Alberto, 300+ balls compared to 1000+ balls. Thanks for the comment 👍👍👍👍
@@Mymatevince you could ask thecod3r very kindly to reball one for you or to even look at it for you to see if he can do anything
Its might just be a dead Battery it will slow it down when its dead until its replaced.. you can google that fact Vince
Hey vince, I found faulty battery’s cause this exact issue. Try a new battery, the only thing I’ve found that fixes this issue.
Please guys like this so he can see, I’ve had this issue countless times and a new battery always fixes it!!
I highly suggest to look around why it is not charging. I had similar slow response when my surface pro 4 battery was dead completely and only was working from the charger. It just slowed down the CPU to not overload the charger, because it needed more current, but was not able to supply without battery.
There's a bunch of us here Vince that love what you're doing, dont let the others get you down.
Yeah, I agree with other users that it's an issue with the battery, though I'm unsure if the battery is serialised and locked in like on a number of iPhone models.
The battery probably was left discharged for so long that the battery controller likely fell into an error state, well, at least I've seen that happen with some PC laptops.
I'm also glad the previous owner remembered to disable tracking (which when left enabled prevents Apple platform initial setup from proceeding).
I don't believe the batteries are paired/locked with the system on MacBooks, at least :)
You’re never wasting our time in a way you’re a good waste of time because it’s entertaining ❤️❤️❤️💪🏽💪🏽
Can’t believe you got it going, amazing, well done! You mentioned a couple of times in the video that you wondered why the short resistance was less when the temperature went up. That’s true for any semi-conductor, which is different from a metal, where the resistance goes up with temperature. That helps you narrow it down to a semi-conductor component on the board!
37:00 the excitement never goes away does it Vince 😜 good job, I can see where this is going
It's great that you got it up and running i'm about to watch your follow up video and see how things are going with this one.
Well done on getting so far. One of the best videos I’ve watched in a while. Sad but I was on the edge of my seat with you.
Well done Vince, i'm sure you will get it fixed with the help of people in the comments! I recently had an old macbook air which had a drink of tea through the keyboard, it would boot eventually but was running slow. After replacing the keyboard it was fixed, also battery was dead but it seemed to recover after fitting keyboard. Good luck, Allan
What a progress there! Congrats, Vince, it so brilliant! Hope there will be another revisit video for this one. 😃
Your passion and joy is contagious! It makes me really happy to see you that happy!
Hey, the fact you didnt give up and got it to at least power on kinda inspires me to not give up easily.
YOU ARE GENIUS,VINCE.KEEP GOING .STAY HEALTHY AND STAY SAFE.
I work in IT, you find the dumbest overlooked "well DUh" stuff when you follow the process.....some ppl get lucky and can figure out where to start the process, but you still need the process. Otherwise it's guesswork. Most people can't figure where to start, thats why I watch the video's, even if it doesn't completely relate to what I'm looking for, it's still good practice to know at least a little bit.
Vince, I love the Way you work on these Items. And well done! maybe TheCod3r can replace the DDR feeding chip with the one on the other donor board, you have at the beginning.
and he may also be able to reball the T2. It's worth a try, isn't it?
And even if not, keep your happy mood :) that cheers me up every time.
Yes Vince! YES! That startup chime was an incredible moment! It's been an emotional rollercoaster watching you (attempt to) fix this mac :)
Yay! I felt real joy for you when you got it! Please put a new battery in your DMM though! It's crying out for one.
That Vince reaction.... priceless.
@vince sometimes people do not realize that watching failures is just as important as watching successful repairs.
11:21 Vince reading off what each pin/trace is for is sort of like the opposite of Louis Rossmann doing it 🤣 BUT he gets results!
Vince I've been watching your channel since you had at least under a hundred subscribers and I love your content so sorry you couldn't get the MacBook working correctly
Don't give up keep searching Vince🙂 Good Job!!
Try using the dead one's battery. Or, like I just read, check the thermal sensors, maybe they are faulty so the Mac think it's too hot to work normally. Nice videos, greetings from Argentina, I have learnt a lot watching you repair stuff.
That jingle never gets old. Litterally sometimes like now me watching this video. I ended up playing the jingle twice. Yes I know some people might say that. That is a bit obbsessive, but come on, you've got to admit it. That is a pretty great catchy jingle. Great job Taz Cat.
Hahaha, I love it, it is too long to play on each video but I've listened to it dozens of times so I'm with you. If 2 of us think it then it must be good!!! 🤣🤣🤣
Thank you so much for your videos, we do not waste any time, we learn a lot and it's precious !
Hello from France
You absolutely crack me up pal, love your work and videos 👍
Great video vince. Have you tried getting hold of some Kapton tape? perfect for screening areas that you don't want to heat up when reflowing.
Great and great job....all of the two videos are fantastic...i love it deeply from my heart.
Amazing video Vince! And you reaction was priceless and I slammed my table too at that very moment. :D
With that said, I looked through some of the comments and I think the T2 chip is fine. I think the power management chip is the one at fault (it did get hot also on applying voltage). I think you can swap out the chip from the other board you have got. I know you said there might not be a revisit with this again but I sure look forward to one. :)
Thanks Arijit, yes it looks like you are correct, I now know the battery is the cause of the slowness, but it is the power management chip at fault on that fluctuating voltage. Cheers 👍👍👍👍
Thump reaction 10/10! Lol.
I know that feeling so well.
Watching your videos, you seem to have progressed from simple switch fixes to very complicated micro electronic fixes , and each one is still fascinating to watch.
Anyway , I'm off to bash a broken rtx3090 with a lump hammer....keep up the interesting videos please👍
Hahaha good luck Adele 🤣 Thanks for the kind words 👍👍👍👍
Such an inspiring video and why only 2.4k views, this video deserves more, this man puts alot of effort in these videos.
I've been waiting for this!!!!! Oh I'm so going to enjoy this!
i like the my mate vince song at the end
good job 👏
perfect timing just finished the first video
Wonderful Vince.
Re-Re-visit is definitely in order.
COME TO US LUIS 👍
I just bought a similar model in broken condition for really cheap (13" MacBook Air M1, A2337). I don't know the specs and it somehow was broken in half. I'm really looking forward for this fix as it will be the newest MacBook I ever tried to fix. I hope I "just" need a new screen as the bottom part looks fine and not damaged and makes the boot sounds when plugged in.
I would suggest to buy a thermal camera so you can find it easier to find a shortage on the pcb.
You should change the battery in your DMM, it can make readings wrogng
Swap the battery! CPU throttles down with a defective battery like this.. I had the same issue is a 2011 MacBook Pro 13'', added a new battery and worked like a new laptop.
I've learned so much from your fault-finding process, thanks Vince! Having a revisit so soon was awesome
great fix vince , i thought macbook air had a good reputation for being fast.
one of the best video man! Loved the reaction to 20v!
My experience troubleshooting Mac are only replacing pieces, I dont know if what i'm saying below is something technically right, thats just my experience using e troubleshooting my own MacBook Air 2012......
Apple's Macbook seems to have some problems when the battery was fully discharged.... For exemple, my Macbook when i needed to replace the battery was impossible to use, because these latency problems... I recomend you to fully recharge it, than reset it one or two times, sometimes it worked for me.... I think its their bios config, when have some problem with the energy supply they force the Mac to run slowly to avoid bigger problems...
Great Revisit! Glad to see you got it up and running
39:20 the most exited I've ever heard him!
Hey Vince, I'm just thinking that another pair of spare multimeter probes with sewing pins soldered to each tips might help while probing around tiny tiny pads.Nice video, handsome.
As others have said, you have a sensor problem. It has several sensors mounted in different places. On earlier models, there was one mounted on the DC IN board and another in the keyboard/palm rest area. You can find software to help you narrow down which one is the problem.
I had the same problem where in the task manager the kernel task took up most if the cpu usage making it unbearably slow. Fans were also at full speed. Guy that fixed the motherboard said it was one of the chips that manages the temperature as it panics
yes. thats what i think it is too. if it thinks its overheating it will throttle everything down. i think it is some i2C sensor.
I did wonder about the battery as well and noticed when you clicked up there it seems to show an error service was needed or something? I was working on an older Macbook Pro which worked perfectly it was just super, super slow and found a faulty battery can cause this, I swapped it over and the problem immediately disappeared. However the fan behaviour was normal and I wouldn't think a 2020 model would have a dud battery so i could be a faulty temperature sensor which was the other suggestion.
Can’t wait for part 3 :D
Great video. The times it takes to do these thanks
Great job is the battery bad question where is the ram and hard drive it least it's works bryce
I don’t I’ve ever herd vince this happy 😂
great video! Very interesting and entertaining. And with all the great ideas in the comments, I think it is worth to do a second revisit video. I would love to see that.
I don't know if this was pointed out, but a bad battery will also greatly affect performance same as the way your Macbook behaves. Maybe swap it out and try booting again to compare? Good luck
I love try to fix is my favourite things to watch
Well done for the perseverance, and I can understand your nervousness when about to test it.
Your the best RUclipsr ever
Are the batteries from the Rose Gold any good? Swap them over.
My guess is that it needs a new battery. CPUs tend to slow down when they aren’t getting enough powe
Something you can try is a SMC reset and a PRAM reset and see if that makes it faster, as sometimes when they get confused it makes the machine run really slow.
Have you tried putting it into recovery mode and put it back to factory settings Great video
Good job Vince, love your honest repair video. Keep it up. 😀
Vince, change the battery and see what happens. When a Mac's battery goes completely flat and you try to charge it, the system kicks into a type of protection mode. Maybe you'll get lucky and that's all it is. I personally seen three MacBooks do this and it was the battery.
Well done so far. Now check why that fan is running constantly! It's probably throttling the CPU hence the slowness.
Come on Vince, you can't give up... you're like centimeters from success. I'd revisit the battery (without a properly working battery, macs like to behave erratically) and also check sensors because the fan should definitely not be running constantly. If it is running constantly, it means that either the cpu (or something else) is constantly throttling or that one (or more) sensor can't be read or is showing something silly. I'd sort these out first and worst case, bring it somewhere to exchange the T2 chip on your boards (if that can be done, because you might loose the contents of the storage if it is tied to the T2, I'm not sure about that though... check with someone more knowledgeable about newer machines... my limited competence ends around 2012 models or so :D).
I'm so happy for you. Good job !
Hi vice great videos , Macbook pros run at less than half speed if the battery is faulty or not charging. Try to change the battery
Nice work on getting it booting at least!
With regards to the horrible performance, a similar thing happened to me a while back. I was attempting to change the battery on my older MacBook Pro. While doing so, I accidentally ripped off the cable connecting the webcam to the motherboard. I was gutted, but figured I could do without the webcam.
Turns out, the cable getting ripped off also broke a temperature sensor on the board. As a result, MacOS couldn't get a temp reading and put the machine in a state where it assumed it was overheating. Hence, the fans were running at full blast, and the CPU was being VERY aggressively underclocked to the point where it was barely functional. Virtually identical to the problem you're having.
Thought I'd share that anecdote, perhaps something similar is happening on your machine?
Thanks for the advice Edward👍👍👍👍
Some other people may have ruled this out, and I don’t know whether this affects the newer MacBooks, since I see a lot of comments saying a CPU issue, but honestly I think it’s an SMC fault, or well, a failure that hasn’t quite happened yet, I have a 2009 MacBook Polycarbonate with a dying SMC so you have to do an SMC bypass whenever it boots up and the fans are constantly running at full and it’s slow, and will refuse to charge a battery or pretend it’s not there.
The PPBus giggles continue.
This is an SMC/Battery fault. Apple had a great idea to put the SMC on the small PCB attached to the battery which is a consumable part.