iPhone 7 Plus "No Power" caused by VDD_MAIN short By STS Telecom

Hi everyone long time no see today, I'm gonna, be working on an iPhone 7 plus that was sent here for no power. I have chosen this iPhone 7 plus for one reason, and one reason only this iPhone 7 plus was actually sent here, because it is not boot looping, that's right. We have an iPhone 7 plus, that is not boot. Looping. Let's have a look at this thing. I'm going to show you where I'm at I have hooked a DC power supply to it and whenever I hook the DC power supply to it.

Our current consumption was right at 3, amps or whatever it maxed out my supply. So that tells me that we have a short on a main power line. So I'm going to go ahead. Where is my little screw? Thingy? Well, there's my screw. Thingy gotta get myself a new TRI wing driver.

This thing is a heaping pile of cow manure and not like an anorexic Florida cow. Either it's a heaping pile of cow manure like a Missouri cow things are still in horrible disarray. Here, I mean it's. It's been a lot more than I expected to pick up and make such a large move as many hours and as much time as I put into planning. You can never really be.

Never really see. Some of these things there's been a lot of unexpected pitfalls that I, just I, could have never ever seen coming so before. I tear this thing apart, I'm going to go ahead and show you what it is that I did that brought me to choosing this one for a video. We're going to connect our DC power here, and I'm, going to push the power button on the power supply watching current consumption very closely. As soon as I push the button, it draws 3.2 amps, which means we have a short on a main power line. So back over to my hands here, we're going to remove the power supply, and then we are going to remove the Bridgett board from this thing.

It's a lot harder to do this in front of a camera. It really is: let's go ahead and remove this antenna looking thing if you've got an iPhone 7, that's not coming on, or it won't finish its power up. This video is most likely not for you. Most of them are all like. Oh, this one's boot, looping! Ok, why is this one boot looping, because they seem to boot loop for pretty much.

Everything? Ok! Is that all over Phillips screws it is, so we're going to switch over, and we're going to use our standoff driver here guess it's time for me to buy a different driver. We're down here this one actually doesn't look. Pre mutilated watch me find a Maine short and then after I get that fixed, then well, that's when we'll discover our base band our chronic basement illness. Now, even though this is a VCC manger or a VDD main or maybe boost yeah not boost, but even though this is a Maine short I'm, still going to check our base band, one of our main base band lines it likes to screw up on almost all of them. Yeah, we've got the sim card in it.

Next, what I'm going to do I'm going to open up an iPhone, 7 PCB board view files here and to decide which one to open up the easiest way is to just flip it over and read the number off the bottom, eight to zero, zero, zero. Two four nine dash a and on here we have a to zero. What oh, it's a seven plus two forty-nine dash an okay! So here's the board, and we're going to zoom in, and we're going to pick out our very most top power rail here and here is VDD main I'm gonna check, VDD main for a short to ground. For that I'm going to use continuity mode, we're going to be taking our measurement in ohms I'm gonna, put my black probe on ground, and I'm gonna, put my red probe on video main, and we're most likely going to get a short. It is reading zero point seven.

So we've got zero point seven ohms to ground in order to narrow down this short as quickly and efficiently as possible. What I'm going to do is I'm going to take my black probe here, and I'm going to hook it in on this side of my vigil and power supply, and I'm, going to hook my red probe over here onto this side of my sickle. My power supply I'm going to connect our ground to the board like that I'm going to set the power supply up here, I'm going to change. My first channel here, I'm gonna, switch this over to four volts, and I'm going to change our amperage just high as it'll go now before I. Do this I want to say that if you get a reading in ohms that isn't like a straight short, let's say you check it, and you get 30 ohms of resistance.

If that's the case, it may not be a bad. It may not be a good idea, just a poor of 4 straight 4 volts to it, especially on prior repair attempts, because what I run into is that sometimes you will wind up somewhere where some low voltage line is connected to a higher voltage line. Let's say you've got, let's say: you've got a GPU line, hooked up to VCC main by somebody. That's worked on this board and there's a short under and I see somewhere or whatever. You've got a one volt one point one volt or some line hooked up to a four volt line, and you check for resistance, and you get 30 ohms well, 30, ohms, and you know I know this isn't going to make sense if somebody doesn't understand the electricity and ohms and the way Ohm's law works.

But if you get like a 30 ohm reading, it may not be a bad idea when you're doing this to start out at 1, volt 2 volts it's sort of work, your way up and try to find it with this little voltage as possible me looking at this board and seeing that we've got a zero ohm short. This is gonna, be a cap somewhere. So in order to find that the most efficient way possible, I'm going to switch my power supply on to 4 volts 3.2 amps I'm, going to hit the parallel button, which is going to give me basically hook. My two channels in parallel, and it's going to give me 4 volts at 6.4 amps- is going to be my maximum output here so, like I, said efficient I'm trying to do this fast, so we're going to turn the supply on, and we are now putting out 4 volts, and we're drawing point 1 amp from each channel, and I'm going to take my VCC main probe here, my anode, my positive lead here, and I'm going to touch this little cap out here, and I've got my hand laid across the board, and I'm trying to figure out which end of the board heats up. It jumps straight to 6.4, amps. Okay.

This can be really hard for me to record I. Guess you could watch my hands. Maybe can you see my hands but turn the light down on the microscope? No, then I can't see that's good. Okay, so I'm going to put six amps of current okay I. Think it's going to be right here.

Under my finger one day, I promise you I'm gonna, invest in an infrared camera. I know there's been at least a couple of hundred of you. That said, why don't you buy an infrared camera and I spent a good deal of time in the past? Thinking that it would just be a waste of money and I would always use alcohol and stuff wait I'm on the wrong. This is the wrong sticker, but now that I've seen the different modes in the way that these things can actually work, I no longer believe it's a waste of money, and if I could do my tool purchase from last year over again, I would be including a thermal camera. So maybe this year, probably toward the end of this year, I'm going to be whips, I'm going to be making another tool purchase.

You didn't see me secretary, that sticker and a thermal camera is pretty high up on my list. So before I pour the coals to this again, let's have a look under the microscope. Let's see by this point, we might be able to visit, visibly see something frying: okay, I, don't see any discolored caps. What I believe I'll be able to get my fingers straight on it, which means I should be able to get burnt real nice and get it here. So, let's see back over to screen-capture, let's look at the bottom of the board.

What are our other candidates here for VDD main we've got a bunch of them. We're going to jump right out here to see 5809 Orfs and actually, let's go ahead. I'm going to I'm going to freeze this board yeah, let's go ahead! Use free spray! That'll make this easier, a lot faster, free spray! Look at me holding the can upside down. You know this is air duster, and you know it's got that stupid detergent agent in here I'll have some official free spray soon this stuff is disgusting for all of you. That said, why? Don't you just use the air duster? This is why, because it's nasty, oh and I, didn't check, am I on the right board just on PM UHF, so it's over here, I didn't check to see if we had any known base band shorts.

It's a good idea to do that. First, because we might wind up finding this VDD main short and then come up with a phone that only boot loops. Okay, we're freezing over nice and frosty well, I'm going to know about nice and frosty, but we're freezing over a little by God, and I'm. Failing miserably, I didn't even come close to see where that was okay. No luck in that spot, so I'm going to go ahead.

I'm going to blow off on my condensation. Let's scroll down just a little lower on the board, see a thermal camera and I would have had this solved already. Okay, so we do have a considerable amount of caps here. I'm so excited to be working on an iPhone 7. That's not boot, looping.

What a klutz can't believe! I just tore the sticker again, let's edit out all the places where I tore the sticker. Actually one should actually be on the other side of the board right. Let's go back to the old-fashioned way and try to feel for heat. This is 12 watts of power. I mean we should start to feel something.

Okay, let's have a closer look. I, don't know if it's maybe the humidity here, but my free spray does not seem to be behaving exactly the same. It seems a bit different okay. So let's use alcohol. I'm going to put alcohol up here around this thing.

I know: there's going to be 30. People say you should just get a flirt. Okay, we're going to look for alcohol to bubble. I! Think I, see it watch up here, I think up. Here's going to be where it's at this is gonna, be a really long, boring video guys! That's okay! I've got big time plans for my YouTube channel, but jeez it took us a long time to get back up and running.

Here I am excited to say we are up and running at full force. This cap right here see 2301. Let's watch that cap once more. Okay right throughout my fingertip wait a minute watch right here! Let watch much right here when I apply current to this. It's to this.

Once more, you got to see what I'm seeing this is. Going to be the first time I've found a short by spatter I say: let's put our alcohol here. Okay, let's add our current and watch this thing. Spatter alcohol on the bench see that right their does. The audio codec have ECC main hook to it.

Audio codec seems to be what's getting hot. How about right? On the other side, yeah we've got this row of caps here, which are directly on the other side of the PCB from this audio codec. So our temperature source suggests that we have a short under the shield. That's what it suggests, and I'm going to cut right here across the sticker, and we're going to start warming. This up we're going to remove the shield I think our shorts going to be right under this shield.

I think I can already see the cap without a microscope all right. So, let's zoom on in I'm going to put you under the microscope. We're going to have a look and see what cap. This is no boy look at that one. We have just been baking the total holy snot out of that thing.

Look at that cap all right, so back over to screen-capture. What's the value on that cap we could just whoa can I control Z that crap? No, we could just I grabbed hold of the wrong eye. I tried to move the window on the capture software instead of the actual software, so we could just remove that cap and move on that might actually be what I do. Let's have a look here, see 35 32 I'm, going to put a little of flux on there I'm going to use these tweezers that have the horrible tips on them, and we're going to grab a hold of that cap and get rid of it. Honey can I help you.

Thank you very nice. Thank you! Honey, yeah, Wow, no kidding alright Who am I kidding. We're going to go ahead and stick this cap back on here. Why? Because it's easy, and I've already turned the pads. Alright, so we're going to stick this little cap down in here.

This is a good little cat. There. We go that's back on there if you're wondering what I replaced that with a brand spanking new 10 microfarad 6.3 volt capacitor. So let's get a little of alcohol on this. We're going to clean this up yeah if you're working on an iPhone, 7, and you're planning on fixing that chances are that you're not gonna, be doing this to fix it because they are notorious for other problems, yeah.

They got VCC or VDD main shorts and standard shorted caps too, but most of the time iPhone 7 comes in for service. It has nothing to do with capacitors. Alright, since I am infinitely confident that that is a fix on this one. I'm going to go ahead and lay our PCB back up here, I'm going to lay the shield way into you. Sort of I'm going to lay the shield back on it, and we're going to start warming.

This up, I haven't put hundreds or thousands of these shields back on yet, as I have on the six through successes, because, typically, if I have a problem under the shield, it's going out the doors and no fix base band fault. Oh, come online up! Okay, we'll take that. Oh, this is miserable. What's going on, don't watch this into a video on how to not put the shield back on an iPhone 7 plus? If you do it slow enough, you can do it without crinkling up the sticker. Okay.

The next thing I'm going to do here is I'm going to go ahead. I'm going to put our stickers back on the bottom, and I'm doing that now, because the board is really really really hot, and I want to move on to my next repair being that the board is hot. That's what I need for these bottom stickers to stick right back on we're, going to go ahead and use our customer screen assembly here, and I bet you. The behavior here is similar in a sense that the battery was directly shorted to ground which the batteries they have protection built into them, which basically is a circuit breaker. It kills the power.

So I bet you when we connect a charger to this. We get a brief. A very brief battery charging icon pick up tools followed by boot, because the battery is not actually dead. It's had a circuit, breaker tripped. So what we're going to do here we're going to connect a charger to the USB? The charger says: 60 Williams, 70 90.

There we go nine hundred million nine hundred Williams and then Apple logo booting. So we are we're gonna! Let this phone boot up see if I can throw the 720 on the screen there. So you can see it as well. Hopefully, I don't have to edit this video, because it showed something that I didn't want the customers, alright we're up to passcode screen. It did not come with a passcode.

I might have it in the computer. However, since this thing booted up so quickly like this I'm, really really really confident that this thing is going to be solved, we do have a working home button and this phone is likely going to be good to go. So I've got a little of reassembly to do here and then, of course, I'm going to check it top to bottom. To make sure base band is okay, make sure it detects a SIM card and make sure this phone is live and well. So this is going to be the first video that I post from my new habitat, a lot of stuff, has happened between the last time: I post, a video, and I'm the, and I'm posting now, but I am thrilled to say that we are back up and running full speed and everybody's happy and everything is well.

I have a lot more to say about our trip and our move and a lot of things that I've recorded, but I'm going to be saving that for a future video, so guys that is it for this video and I hope. You all have successful, repairs and I will see you soon. Thanks for watching have a good day.

Source : STS Telecom