Missing PM_SLP_S4_L signal on Macbook Pro 820-2330 logic board.

Missing PM_SLP_S4_L signal on Macbook Pro 820-2330 logic board.

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okay so today we're going to be going over an MCP 79 bass board that does not turn on and it is a problem that is not BGA related so a lot of people like to think that this is a BGA problem and one of the things that I try to do on this channel is I try to inform you I try to teach you and one of the things that I try to teach is that you should use your brain and have a proper understanding of how a circuit works instead of buying into this culture of just replacing things for no reason or flowing things for no reason heating things up in an oven for no reason and the thing is if you heat this it will work again but not for the reason that you think think of all those people on the internet that are telling you to do things because of the solder balls and those cheap let free Saturday laws it is for the most part they're just dumb they don't know what they're talking about and they're just giving away really really shitty information so as you can see I'm plugging this thing in I'm getting a green light my charger but when I short the pads turn it on it does not turn on so one of the first things that I'm gonna do the thing that I tell all you guys to do when you have a board that has this type of issue is you're going to go through your list of power rails and see which power rail is not present so this is an 8 – 0 – 26 10 motherboard which as I like to say is an old piece of crap so we're gonna go through the list of power rails here and I'm gonna show you what's going on how this works so that you can hopefully learn something I'm finally figuring out what Adobe doesn't like when I use these shortcuts like control one two and three for open broadcaster all this doesn't like when I use those two in Adobe it actually screws it something in Adobe so I'm starting to figure out the things that that make my videos wind up being a mess anyway so let's go over to the a20 26:10 board and start going through the power rails in the machine so this is one of the older ones where you get this nice block diagram on the newer Apple products you don't get that the block diagram you get a middle finger now let's see power rails is gonna be getting close okay so let's just start testing we have pp bus g3 hot let's see if I have pp bus g3 hot I'm gonna take my multimeter probes plug them back in and we're gonna go over why this is as always a circuit problem not a BGA problem because I'm cheating by the way I know what's wrong with this I haven't measured this board I have not measured it it's just I've been fooled by it so many times and recently I got fooled by it even though I've done this so many times and got owned by it until this intelligent gentleman named ooh gonna form that I'm on pointed out why I was being an idiot and I realized that I was missing something that I had done a million times before I was actually heating a certain part of the board and right under it was that was the point that was the issue and I thought the thing that I was heating on the top was it and it was just driving me nuts and I want to actually wind up looking on the bottom of the board and I saw the position of it I'm like you but anyway moving on so this says on this board that PP buzz G 3 ha is supposed to be 6 volts I don't think that that is correct let's see on this board it's eight point three so the schematic is wrong I know that because I've measured this a million times I know that my DC and rail is good again there's no reason to measure the DC in rail when I have any type of rail on the machine working the way it's supposed to I know the charger works there's no reason to measure P P 3 P 4 – as I've mentioned in other in other videos that is the for the one wire circuit the one wire circuit works off of P P 3 V 4 – which means that if I have a green light on my charger the one wire circuit works which means P P 3 V 4 200 G 3 hot is working just fine now let's measure 4 PP 5 V underscore s 3 that's the next rail PP 5 V underscore s 3 and I measure that and when I measure that over here let's see what I get so I'm PP 5 vs 3 I get 0 volts now as I said before you start trying to figure out if there's a problem with the chip with the with the circuit see if the chip is actually turning on so let's scroll over to what creates PP 5 vs 3 you can do it PDF reader okay so you 7201 now as I've said a couple of times look for enable pins or in trip pins or something that tells this chip to turn on so the enable on this is coming from p5 vs3 enable p5 vs three underscore enable that comes from PM sleep s4l now do you think PM sleep s4l is going to be good on my board or bad let's measure so that's where it shows up when I measure PM sleep s4l I get sits right next to the fan connector on this probe point well that's not really a good place to measure let's try on the resistor above I get zero volts now let's see where p.m. sleep s4l comes from some reason how it's switched over the microscope oh well hey just to go back over that in case was missed PEP 5v underscore s3 is created by u 7201 the enable 10 of that chip had the enable signal comes in through p5 vs three underscore en I look for pv 5 vs 3 and to see where that came from that comes from PM sleep s4l let's make sure open broadcasted and switch on me it didn't now we look for what PM sleep s4l comes from and we see that PM sleep s4l which is going to be needed to enable PP 5 es 3 comes from our mCP 79 which me and the mCP 79 is also the graphics chip so what the average person is gonna think at this point is they're gonna think that the signal that is missing comes from the graphics chip the graphics chip burned out I need to replace the graphics chip I need to buy a new one I need to solder a new one on there this needs BGA rework right wrong well let's go over what powers the mCP so the MCU because there's a list of power rails here and again that's the thing like I've solved this problem and I got to a point where I had this problem and I edit so let me just heat the BIOS chip first because for some reason I just decided to be a monkey that day and do the same that everybody else does and heat BIOS chip and it worked and what you're gonna see is right under the BIOS chip on this board is my problem spot so okay so let's scroll over here and see if there's anything of interest to us so here are certain rails P p1 v 8 1 v 5s o MC P now we're not in an Esso state so I'm not gonna check in SL rail yet P P 1 vo 5s o MC P again I'm not in an Esso state I'm in an S 5 state I'm off I'm not really interested in that P P 1 vo 5 s 5 MC P ok that's something I may want to check that's something I may be interested in so let's take a look for it so that creates PP 1 V 2 R 1 vo 5 underscore s 5 so let's look for that that's supposed to be 1.5 volts according to the schematic here P P 1 V 2 R 1 vo 5 underscore s 5 so that's created from the you 7750 chip you 7750 chip okay so this is a buck converter that's something that you should know if you watched any of my other videos now let me explain to you the the sheer amount of idiocy that I've seriously why does this keep switching over what key am i hitting on this keyboard to switch the camera over as you can okay just since I don't know if you actually saw the stuff that I was looking at I'm gonna scroll back to it I said I'm gonna get a second monitor for open broadcaster so it stops trolling me is it is it when i zoom in and out in a PDF file that's doing okay so what I was looking for is a power rail for the mCP because I wanted to start checking all the lines and what I see here is a bunch of soo rails but then there's also an s5 rail which is a relative to beyond that powers the mCP on the mCP itself is not even the computer itself is off so I searched and I found that that power rail that s5 power rail is provided by you 7750 so that creates pp1 vo v underscore has five MCP this tells me that is a 1.5 volt power rail that are supposed to be present on the mCP when the MC when the machine is in an s5 power state meaning the machine itself is off so if you see s5 that's the power state that should be present when the machine is off as three that the power state that should be there when the machine is sleeping as oh that's a power state that should be there when the machine is on so let's measure that let's measure that along ll 7770 and what I'm gonna do over here is I'm gonna go over all the stupid that I've done to learn what I've learned okay so when we measure over here that's supposed to be one point zero five volts and when I measure on that inductor what I get is gonna be let's if I can put the multimeter where you can see it oh my kidding that's almost invisible there oh well you'll just have to trust me when I read the voltage then I suppose it shouldn't be that hard so on high measure on that and dr. what do I get the spot 0.317 volts let's see if I can hold this here see how good my chopsticks sir see that that's not one point zero five volts so let's talk a little bit about what could be going on here so what most people are going to do is they're going to think that the mCP is bad and that's bringing the line down and they're going to replace the mCP or they're gonna reflow it and well you know what's really really sad here the sad thing is that it's actually gonna work again and they're gonna think that it's because they're the mCP I bet solder ball is they're gonna think it's because the mCP had some kind of maybe the you just reflow the inside of the chip whatever silly theory you have as to why that made it work again people are gonna believe it now what I thought I know I already know that's but I believe it or not at one point I tried it and it worked and then it died again I didn't know why what other people are gonna think is that this power supply here is not working or one of these transistors is bad or this controller is bad something here is not working they're gonna drive themselves absolutely batshit insane going through this circuit on the screen over here trying to figure out what doesn't work and they're gonna think of something over here now what I want you to think about is this what components in the circuit is going to be affected by heat think about what the come with the makeups are these components an inductor is a coil this chip here is just a bunch of integrated circuits of transistors and resistors whatnot inside of it these are just resistors the one part of the circuit which one of the components in the circuit is known for it's intermittent nature it's gonna be a capacitor the capacitor is known as a part that can sometimes work sometimes not sometimes work sometimes not sometimes work sometimes not so I was heating this thing and it would work again and then would die the beginning I really honestly thought that maybe it was the mCP later on I realized that had to be something else and again I was I was so close what one point in time even after having replaced the stupid little capacitor at least ten times that I have a whole spool of them here I was so close to actually replacement he replacing the BIOS chip again that I just think I'd like I replaced the BIOS chip and it worked and then I died i heated the BIOS chip it worked and then it died I put another one on there at work and then I died so on this board right here is the BIOS chip right on the other side of the board is the capacitor so let me show you the capacitor that goes back the capacitor that goes bad over here is C seven seven seven one and one of the hints that I should have had one of the hints that I really should have brought this out to me based on my history and with recording consoles is the fact that this capacitor is made of tantalum so I can zoom in because the PDF reader is being a piece of crap fortunately but right over here you see this where it says poly tant tantalum is a miserable miserable type of capacitor for one reason to me and I have some really bad memories attached to it tantalum can actually make you sick so when a tantalum capacitor explodes like some of the tantalum capacitors that they have in these old consoles when the capacitor itself explodes you can you can get a good 102 fever over the course of just a few hours from being in the room to inhale that so I know that I hate tantalum I have I have a natural hatred for capacitors that are made of tantalum and one of the things that you'll notice about tantalum capacitors and one of the reasons they get used is they're they're pretty small compared to any other type of capacitor so this is a the tantalum capacitor right over here it doesn't look bad at all and III just I should have known the sleeve so what I do is I replace it with a standard polymer capacitor instead of a tantalum capacitor you can replace it with many different types I just chose to 330 microfarad capacitor rated for the same two volts and here's the thing the problem this so I have to get away for this to fit here and that is going to suck but we're gonna find a way to get this to fit in here because this will provide a good option this is actually gonna work it's just again it takes a lot of finagling and which we're gonna be going over and we're gonna see if this actually works when it's done now one of the things I wanted to put the camera back on so you could see I was actually gonna take it off for this because I was gonna have the other person here help scrape away the pads is that somebody else at some point in time figured out this problem because watch what's gonna happen when I use my my he had his liquid flowing away that's flux so that means that somebody else at some point in time probably refurbished this board because the flux is right around the component that I said always goes bad and what they did with that we're not gonna do is they reused the tantalum capacitor that I said that you're not supposed to use so they probably took another tantalum capacitor off of another ship board and put that tantalum capacitor here and it died again again so you may think that this is silly that I'm gonna be using a different capacitor than the one that was intended but I'm using a different one because I have a fundamental district for tantalum and as silly as it may seem it is well founded on the fact that these things have made me sick not only have they made me sick but they also cause the board to stop working so they heat this thing thanks a lot of heat to get this damn thing off now here there's no reason to remember orientation the reason I don't care about the orientation of the chip of the capacitor is because the capacitor that I'm installing is not a polarized capacitor if you're installing a capacitor that's polarized you have to worry about the orientation of the chip but when you're installing a capacitor that's not polarized you have nothing to worry about here it is completely acceptable for this specific application that we don't care for using a polarized or a non polarized capacitor either one will work fine again the only trouble here is going to be how do you fit that in there when there is no space so the first thing I'm gonna do is turn the pads so that I can properly remove all of the solder and all the junk on there so we can get it nice and flat and then we can start scraping along on both sides and then so you know a capacitor is a component that when you heat it you can actually get it close back to the original value and get it working the way it was again that's not necessarily true for every type of component but it is true for a capacitor all right so that's replaced so let's just get a little look what that looks like under the microscope I haven't cleaned it off the board yet I'm not gonna I can't tell you that this is a nice looking thing in the world but what I can tell you is that most likely will work so let's just find where what I did is and that is that's this pile right here so that's the capacitor there we go yeah so that's that that's the new and large capacitor and I also I move the coil up because the inductor was actually keeping that from working so Jess always says it's not the coil sometimes it actually is the coil the coil is in the way of my new capacitor fitting so let's see what we get now I'm gonna take my DC n board again a lot of people think they heat that component after they heat the component that works because when you're not heating the mCP you're heating the capacitor next to the mCP and you're making that cap work again for a short period of time so let's see what we get before we add point three volts now we get Milan says we get pouf this is his board so hopefully we don't get pouf 1.09 one point we're supposed to get one point zero five one point zero nine I will certainly settle for because that's good enough and so when you see these voltages in the schematic one of the things you need to understand is that there's tolerances so if you see five volts and you measure four point nine nine nine that doesn't mean you need to start troubleshooting that rail that means that you need to start going on to what the actual problem is so I'm gonna short the pads see if it turns on and as you can see my fan spins which here is the ultimate test that the board works and that no further testing is required send back to customer kidding but you get the point here so if this was the repair do you and I'm gonna wind up doing a video on this on BGA rework in general because I feel like a lot of people jump to BGA rework just to kind of make the excuse to themselves that they can't fix it when it's not a BGA problem this board does have BGA problems it has an L VDS MUX chip that goes bad by the way this chip goes bad ten times more often than the GPU does and it is a complete bitch to to work on but these boards do have BGA problems but they're not the BGA problems that you think a lot of people get caught up in this idea of replacing BGA chipsets when the BGA chipsets are not the actual chips instead of at fault its power going to them it's signals going in and out of them and you know I'm trying to get you out of that culture that mindset of just like oh there's being a monkey that replaces chips for no reason without thinking without looking without no I don't want you to be like me eating you know eating the who would being somebody who actually went through this already over the course of several years is heating the bioship because he's just being an idiot

18 Replies to “Missing PM_SLP_S4_L signal on Macbook Pro 820-2330 logic board.”

  1. ben wrong

    I had a board with no pm_slp_s4_L (4.5v)…. so i removed the smc to replace one on another board with hibernation issues….. funnily pm_slp_s4_L became an issue on this other board… .. Can the smc cause this or is it likely an intermittent coincidence?  I have since replaced with a couple of other smc's and have ended up still with hibernation issues….. smc_lid is 3.3v (on multimeter) though i suspect a component on smc_lid is earthing intermittently or just enough to trigger smc……. sadly cannot check trace to smc pin without removing it again…..

  2. Jonathan Langdale

    I purchased a multimeter and followed these instructions to diagnose that I get 0.37V for L7770 on my 820-2610-A. However, I don't have the tools to replace the capacitor and rearrange things.

    Can anyone recommend someone near Montreal?

  3. Chuck G

    So … if 1.05 is present but still no PM_SLP_S4_L  (on an 820-2533, everything needed is present up to this point) … MCP problem then? I'm chasing the proverbial rabbit on this board.

  4. reaper reaper

    I have the exact same issue, only difference is that PP1V2R1V05_S5 is present (1.10V). Does this mean dead MCP/BIOS? Oh, and I checked pretty much every S5 rail I could find in the schematic, all is good there. I also tested C7771 and it shows 330 Ohms.

  5. The STiVo

    I can't believe it. My late 2008 2.8GHz BTO MacBook Pro was in the junk box since 2013 because of no power. Watched your video. Purchased a $1.78 capacitor. Replaced it. AND IT FUCKING WORKS! YOU ARE THE MAN!! THANK YOU! =)

  6. Tony Tone

    What points do you short the pads to turn on? I know on the iPhone bc there is the power button to ground. But how you do dat?

  7. Pete Art

    Thank you Louis!!
    You are a hero in many ways! 🙂

    Replacing C7771 did the job. I've put in a 220uF/3.9V type "pc-con" capacitor; "PC-CON is a Conductive polymer aluminum solid electrolytic capacitor which using conductive polymer material for the negative terminal as electrolyte in the aluminum electrolytic capacitors. It has an excellent ESR (equivalent series resistance) characteristic particularly in the high frequency zone".

  8. Erdal Fazlaoglu

    Louis great channel 🙂
    louis, i am trying to find a induktor on the A1278 logic board in the schematic FL4501 and FL4502 Inductor. but i can find it on the board view. way?

  9. triblackcorvette

    You rock Louis. I have 3 boards doing this exact same thing 820-2330's and got to the point of putting them in the oh well pile as all rails appeared to be there except that one and traced it back to the GPU and gave up. I am going to get them out and check this C7771. Thanks again

  10. daaudiome

    Luis I'm having a similar issue on my macbook pro I heat up the area near the EFI BIOS chip and after some time I get 1.05 on a test point I found. The strange thing is that once the magsafe is plugged and I heat up that area, I have to unplug and plug again for that MCP voltage to come up. I have an LCR meter, I wondered if you checked the value of the tantalum cap you replaced to see if it was 330uf. Can you check tantalums same as electrolytics with an LCR meter? thank you louis.

  11. Chris Long

    Louis have you looked at Digikey or other sources for a cap that will fit easier?

    Thank you again for another very informative video.

  12. zac smith

    You just earnt me money. Ive been chasing this one for a while.
    Nice one, never think to look at capacitor values really, but ill keep an eye out for tantalum ones in the future.

  13. Shahrukh Bakar

    Excellent video. I had messaged you earlier regarding an 820-2879 that had a missing PM_SLP_S4_L signal and had traced it back to the MCP as you mentioned. My next step was to check the clock signal to see if the MCP itself was bad but I don't have a DSO so I gave up on the board. I'm realizing that checking the enable pin voltage was the correct thing to do. Unfortunately I recycled the entire computer because I was moving shortly and didn't want to take stuff with me. I'm really kicking myself now for not checking the enable pin signal and corresponding circuit…if it really was something as straightforward as a capacitor I lost out on a perfectly functional FREE MacBook Pro!!!! At the very least I should have just put it into an oven just for shits and giggles before giving up on it, even if I didn't keep troubleshooting further. It was a very clean board too despite water damage. Lesson learned…

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