Repairing an iPhone XR with "No Image" - What I found inside this phone was horrifying!

hey everyone hope you're all doing good today i'm working on an iphone 10r that was sent here for a intermittent image problem i started this video because what i'm finding inside of this iphone 10r is absolutely horrifying hey jason i have an iphone 10r that has a short somewhere that keeps the screen from turning on the phone turns on fine and everything works perfect even the screen for about 20 seconds then the screen turns off as if it was locked and never turns back on restarting the phone right away doesn't show any apple logo or anything so something must be getting hot enough to keep the screen from turning on let me show you what it is that we're up against when taking this phone apart everything appeared to be pretty well factory i mean it did come open pretty easily so i could tell that it had been opened before but looking inside the phone all of our black paddy stickers and everything inside of this phone looks to be genuine like you can't tell that there's been a lot going on here so after removing the screen the first thing that i did here was had a look at the display connectors and i thought aha i mean these look really crummy i'm not sure if you can see exactly what i'm seeing with my eyes but this looks really bad like there's gunk all down in these connectors now these connectors the pins they have a way of getting recessed back up inside of the connector so if we buzz right along the connector here you can see that we've got some gunk in here that really doesn't belong i'm not sure what that is it kind of looks like uh i don't know maybe old flux or something i'm not sure but then this other connector you can see that this first pin it is recessed way back up in there to where you can't even really you can't even see part of it so i thought aha this is going to be an easy fix just clean the connectors right well clean and fix that one pin there that's all out of whack but then looking closer at this board i start to see things that are genuinely horrifying if we zoom in right here next to this display connector you'll see that we've got a ball squeezing out we have ball squeezage this component down here looks as if it has maybe gotten hot or something now let's just move right along the board here there's our doc flex connector and here's our battery connector now just next to this lower antenna connector we have more ball squeezage and this component here looks as as if maybe it's been reballed or something it's definitely been like scrubbed on see how we've got the the corner rounded off of it these ics they normally have really really uniform straight 90 degree edges but this one has the plastic on top is rounded off so yeah and then also look how offset that bottom shield is that is just that is absolutely horrifying because that bottom shield it's not easy to take off at all this is a customer that is also concerned about their data so i've received a 10r here from a shop that it is booting with no image i verified that but on the 10r what i'm seeing here with that shield being offset balls squeezing here and there that is not good news on the iphone 10r and since the rest of this phone appears to be completely legit like something from apple this is most likely going to be some sort of a nasty refurb so i know that it is booting without image let's see if we can get lucky i'm going to go ahead and i'm going to move toward cleaning the display connectors and then also fixing the wonky pins that are sort of sunk back in there and see if this thing will get an image so first we're going to get this pad sticker thing out of the way because it's just going to get all funked up with alcohol so let's get some alcohol on here yeah i guess this video is also going to be to somewhat cover my butt as well because this phone although it is doing exactly what they said it was doing sort of i mean they said it was getting an image temporarily i have not gotten this thing to get an image at all and honestly with what i've seen just with a brief microscope inspection i'm not surprised to see that this board has problems we're going to go for the easy fixes first because on a board like this i'm honestly kind of scared to touch it it's already worse off now than it was whenever it came in and i hadn't even touched it so all i had to do was breathe wind onto this thing and it went from sometimes getting an image to never getting an image all right let's clean these connectors the best that i can did we disconnect the battery yeah we got the battery disconnected oh yeah squeaky clean can you hear it squeaking well i'm not so hopeful now now that i have scrubbed around on this connector we can actually see that those pins are exposed these connectors the pins have a way of getting pushed back up inside the plastic and it'll cause them to not get connection you'll get proper diode mode and resistance mode readings but you still won't get a good connection and it can be maddening i've reworked entire backlight circuits and things because of a recessed pin before that's sort of embarrassing okay well with just a brief cleaning of those pins let's connect a screen and see if this is any different i am really horrified about seeing balls squeezed out i mean i suspect that this is a refurb that the customer has been using so if it's just something as simple as a dirty pen we're going to go with it let's get a test screen here is my little bin of goodies here we got a uh let's see we've got iphone 6 screen another six screen oh here we go yeah how about this one ipod 4th gen can't ever have too many of those on hand i actually do data recoveries on there okay iphone 10 that's a 7 pro 11 11 pro ah xr the last one i look at how about that so here we have an iphone 10r screen right here i'm going to turn the power supply on watching that current very closely 10 milliamps that's completely acceptable now we're going to press the button to boot and one two three boot now all we've done is clean the connectors right i knew we wouldn't get so lucky not on this one not with ball squeezage everywhere so we can tell from the dc power supply that this phone is actually booting i'm going to give it a little longer here to finish booting and then we're just going to turn it off but with the little stickers removed from around the connector you can really see that this shield has been off of there before i mean quite clearly the shield has been off of there before what in the world was done to this phone is this like an entire ground-up refurb i mean that shield was not soldered back on there straight you can see that bottom shield is all wonky what is causing this thing to all of a sudden not get an image since the rest of the phone is working oh look we've even got you know that little black adhesive that goes on next to the board we've even got that so i've got the board out of the phone now and you can see that somebody actually went through great lengths to make this look factory they've even put this sticker back on the side oh yeah we can definitely tell that that bottom shield has been soldered back on it's been off of there and soldered back on oh yeah for sure looks like it was soldered back on with an iron huh how about nand what does nan look like a bunch of goop all over it alright so let's peel this sticker off the bottom here come on baby trying to keep the adhesive on the sticker and not on the board there we go there we go so i got it off there with the adhesive stuck on the sticker not on the board just so it's not picking up crap off the bench and let's look at it dude this thing is in terrible shape this is an ugly ugly nasty refurb has it had nand carved out i actually don't think it has one side of it sort of looks like it has this side does um no image okay well let's start at the display connector so let's have a look at the board view sorry paul we're going to be using foam board today because i don't have a board view file for the xr to be used with flex board view we're just going to go down the connector here and take some diode mode readings the first pin here is a data line getting a 1.4 that seems to be massively high is that actually a data line what is that line oh that's one of our av ddh lines so to test that it'll be necessary to reverse our polarity so back black probe on ground red probe on our pin 0.59 that's acceptable so let's go on down the line here i believe the rest of these are going to be data lines so we're getting a 0.0 that is our ground next one is a data line 0.3 data line ground point three point three ground so it's data line data line ground data line data line ground point three that's right point three that's right ground and then we should have two more point threes that is right now let's check the other side of this connector 0.25 it's a little low so i'm going to zoom in on the board view here and have a look at what that is 1v8 it's ok for 1v8s to be a little low 0.43 0.60 that's on our third pin down panic be calm i'm getting an open line on our fourth pin check it with reverse polarity okay nothing there so looking at the board view we are getting display test what the hell is that let's ignore it so 0.3 on number five a 0.6 on number six let's see what number six is reset con l that might be a little bit high for that pin you know i don't have an xr board here to compare this against yeah so we're getting at 0.67 that's almost a 0.7 on the reset line 0.42 0.56 39 5 6. five six three nine and five six so this reset line that is troubling that's almost a 0.7 i would expect that to be lower than that i really would so next to the connector here we can see that this line from this pin it's got a cap and then it's going through this resistor now it's actually not a resistor it's an fl it's an inductor and then we have a resistor to ground so this is very much the same exact circuit that we see on like the the 6s and other iphone models so we need to look at fl 5752 and check these components here so looking at that connector from this orientation that's going to be the one to third component down that's these components here and i'm going to go ahead and get a diode mode reading on that component itself to see if we can tell if it is bad so we'll just get on one side of it here we're getting a 0.6 and a 0.6 on both sides so that's most likely not bad and then the resistor that we see on the board view apparently that isn't no stuff because i don't see it on this board there's a gap and then what it looks like is most likely another inductor and we can check across that inductor here and we should get around a zero yeah there we go 0.00 across that inductor so nothing too fishy there where are the guts of this thing where are the display components let's look back at the board view because those readings are actually all looking pretty good on that connector let's see one of these was a 5v7 line right all right 5v7 all right where does this go so we'll follow it through this inductor that line is all the way over here and then our chestnut ic is actually right here u-5500 so back under the microscope i'm noticing here and inspecting the shield that is over u5500 look at this we've actually got unmelted solder paste all around this shield this looks like complete total garbage look at this none of that solder paste melted and they just left it on the board holy smokes okay we're going to go ahead and remove this shield i didn't get any immediate bad readings at the connector so with a board that looks this bad it's going to come down to visually inspecting it i'm going to go ahead and remove the shield that's covering chestnut so we'll get a little alcohol on this sticker and get this out of the way now i don't mind these upper shields too too much it's the lower shields that cover like the baseband components that really bother me on the 10r i would like to see how in the world apple put these things together using such a high melting alloy on that shield i mean you almost almost have to melt the solder under the components to remove that shield but not quite you can do it see a lot of people cutting them i typically use low melt and hot air okay so i've got my hot air set on 430 degree degrees c and we're going to start warming this up carefully watching for something to melt yeah the shield on the cpu that's pretty low melting alloy this shield here isn't too bad but man these lower shields down here what apple did is just evil they have got the highest melting alloy i've ever seen in my life inside of a phone now also it is worth mentioning that sometimes with no power 10rs you'll find a shorted cap right next to the pmic which is under this sticker so there are some that you can repair without removing this shield of course i've always removed the shield and then later on figured out i could have done that without removing the shield oops i've pulled it out of holder too aggressive okay some movement damn i pulled it out of the holder again okay time for me to get a new holder there we go all right let's see what this looks like behind door number one shall we dude this board this looks really bad i mean really really they have like now how in the world did they manage to squeeze all these balls out everywhere look we've even got a ball down here between these coils i think how do they manage to do that but not melt the alloy on these pads like i just removed the shield yet this alloy still did not melt it's almost like some half wit tried to use the same high melting temp alloy up here as what apple uses down here on this shield which is just horrifying there is just too much carnage here this is a phone that is supposed to go back working with the data intact because after all i mean it did just have a simple problem right no image this is looking an awful lot like a no fix boy somebody has really had some struggles with this board i think it is absolutely a refurb really am tempted to have a look under chestnut i mean this thing is absolutely disgusting though like if i get image working on this there is no way that i could send this back as a repaired board in good conscience this is uh this is completely gross just imagine all of the same squeezage that we got going on around all these components we've got like a whole row of components down here with balls squeezing we got balls squeezing here this is just awful and down here it's got like somebody left some somebody left some snot on the board for me but just imagine with all of these balls squeezing what does the underside of the cpu look like it is an absolute miracle that this phone has ever been able to boot up and work but i'm betting from the description that this is a phone that the customer has been using and they genuinely genuinely brought it into a shop for repair and said please fix it without erasing my data this thing needs a lot of work at the very least if i'm going to fix it with all the balls everywhere it still needs to be ultrasonic clean because there's like snot and corrosive some sort of ominous fluid all over the board that's corroding components this is actually a pretty big repair to try to fix that is a stopping point for me on this one because if i continue from here i could be sort of digging myself a grave as it is at this point i only have evaluation time in on this and i need to communicate with the customer and say hey if i can get image working on this i'm nowhere near going you know there's no way i can guarantee this to be a fully functional phone because this is absolutely nasty but i need to see if they are after just the data and if they are i may try to repair it to a point where i can send it back to them at least working well enough that they can access their data now on phones like that phones like this i still try to create a local backup before it gets shipped otherwise i mean what are the odds of this thing getting back to them and not working and probably pretty significant because it just it looks bad really really bad so i think that's going to be it for this one for now if i continue this i'll come back to this video and add more to it otherwise i may post this video exactly like it is all right i am back with this one i've gotten the go-ahead from the customer to proceed with the repair for the sole purpose of being able to access the data let's have a look again at these connectors i've got it under the microscope and zooming in looking at the display connectors again these just this looks really bad looking at the pins along these connectors do you see how we've sort of got like a some sort of a substance bridging between the pins and then down inside the connector we've actually got the same substance like down in the bottom some sort of a gooey it's all down inside of the connector the camera really isn't doing this justice so we've got all this stuff i mean this looks like liquid damage right i mean this looks like some sort of a re-solidified solid that was once suspended in liquid and that's all down in between all of these pins this could actually be causing us a no image problem now i suspect that that's all under the connector as well since we've got it like here along the pins and i can see down inside this connector it's just all down into the bottom of here so whatever this is is absolutely nasty first thing i'm going to do i normally don't do this first but i'm actually going to ultrasonic clean this now since i don't like removing these bottom shields but obviously somebody else already has i'm going to go ahead and remove the cpu shield and we're going to be ultrasonic cleaning just from this part down and let's see what we get so let's get the cpu shield off of here now much like other refurbished boards this one has a little strip of glue here where they've put a strip of glue along the top of the shield so we're just going to go ahead and apply a little heat and peel that out of there i'm really curious to see what this looks like under the cpu shield anyways right all right so we've got the glue out of the way let's start warming it up to remove this shield now the cpu shield on these it comes off pretty easy it's not like these bottom shields that are an absolute complete total nightmare so i'm just going to sort of grab a hold of it and apply some light upward pressure see it's starting to move oh yeah baby calm to papa yep it's exactly what i expected balls squeezing out all over the place i mean look at this board holy smokes this customer was using this phone and then one day it just all of a sudden stopped getting image i mean really look at this thing that is madness you know what i'm seeing i'm seeing that the cpu has been replaced not replaced but rebald and put back on and man they just got solder swelling all freaking over the place cpu has definitely been carved out of there let's get it out of the holder so that i can flip it around and work with it what is it with me getting bored sent here for no image that our prior cpu recalls oh yeah definitely a cpu reball we can see all under the edges of the cpu i feel sorry for the customer that bought themselves a nice brand new 10r and didn't realize that it had this sort of carnage going on on the inside i mean if you like balls this is definitely a phone for you so i'm sort of starting to switch my tone here i'm thinking that maybe it's not so much likely to be due to an issue with the connectors as it is going to be an issue with balls squeezing everywhere and also this thing being a prior cpu rework attempt i'm just going to brush some of this stuff off of here now i got to say they did do a really good job of reballing the cpu and not swelling any solder around the main pmic but boy they sure swat swelled the solder around the wi-fi i see holy smokes why i'm really tempted to flux that cpu and give it a float because that may actually be all that is wrong with it okay well just in case this is just simply sometimes it's hard to judge a book by its cover even whenever the cover looks really bad but just in case this is just an issue with salts between the pins on the connectors i guess i could check with a multimeter but this looks really bad what i'm going to do i'm going to go ahead and ultrasonic clean the top end of this board so that i can see much more clearly what is going on and also if it is just an issue with the connector with nasty stuff then it might actually get image working so i'm going to go ahead and ultrasonic clean this and i'll be right back all right let's see if we can make this nasty board just a little bit less nasty with my nasty ultrasonic cleaner shall we actually out of branson ec it should be arriving today though so i'm going to try to just go right up to those bottom shields because i don't really want to get it wet under those bottom shields we're going to give this about a minute 30 seconds on one side 30 seconds on the other side it's about 30 seconds i'm going to rotate it i don't think it really matters to rotate it but i believe the the transducer or whatever it is that makes this god-awful noise is pretty well getting one side better than the other i don't know if you can see that or not but i have just literally got flux clouding off of this board see the cloud coming off of the board it would be a lot easier to see if my ultrasonic cleaner was actually clean but look at that cloud the flux is literally just clouding off of this thing now after ultrasonic cleaning we're going to use a napkin and just sort of soak up as much of the ultrasonic cleaning solution that we can and then once i'm confident that we've got enough of that liquid soaked up we're going to throw that napkin away and grab an alcohol bath now i don't want to completely sink this in the bath because i didn't remove these bottom shields and i sort of don't want to get that wet down there so i'm just going to turn it up on its side here and flood as much of this as i can we're just trying to displace the water with alcohol we're trying to get rid of the cleaning solution and replace it with alcohol that evaporates much much easier now it's hard for me to get the alcohol up here on the connectors that i'm so worried about but when i turn the board over we're actually getting it on the connectors now once i am confident that we've sufficiently flushed this board i'm going to take a fresh napkin and soak up as much of the alcohol as i can the next thing i'm going to do is actually place this board on a pre-heater so to dry this board i'm going to set it nicely here on this preheater and i'm going to turn the heater on to a temperature that is not hot enough to melt solder or actually hot enough to boil water even because we don't want anything swelling i'm hesitant to say exactly what temperature i'm using because this thing is not calibrated and your temperature might be different than my temperature we're going to set this heater i'm going to start at 195 degrees c after about an hour i raise that temperature to 200c after about two hours i'm going to raise it to 205 c now that's as high as i go i'm going to leave it at 205c for two or three hours i just really want to be absolutely certain that this board is dry because there's a good chance that i'm going to have to use hot air on it and let's say you have a little bit of water between the ram and the cpu or a little bit of water trapped anywhere on this thing and then you go grabbing a hot air gun and heating it to 350 degrees c that water swells up and can pop you can literally cause it to snap crackle and pop and absolutely destroy this thing so it's really really important to make sure it's completely dry so with this thing set at 195 c i can actually lay my hand right on it and it's just like it's really warm it's not what i would consider to be hot maybe without the gloves it might actually burn me a little bit so it's a pretty low temp i'm not feeling like it's actually 195 c all right boy has it been a really really long day i am back with this thing it has been on the dryer all day long and i'm confident that it is completely bone dry so let's have a look at it and see how much different it looks so you can see my ultrasonic cleaner has did this thing quite a bit of good there's no longer any visible flux around any of these components the solder balls the unsolidified solder paste that we had all along here is all gone no longer any carnage showing there let's look around the cpu oh yeah it's cleaned up quite nicely you know there's a chance that simply ultrasonic cleaning this will get an image to work again for two reasons some of the flux that was around here could have had like other stuff mixed with it and caused it to be conductive but also the display connectors these looked they looked okay but they had like this bridging going on along the sides of them here where there was like some sort of substance some ominous substance that was bridging between the connections both along the pins as well as down inside of the connectors now i have a little bit of a confession to make a lot of you already know this but many times when i'm recording a video i i sort of get caught up in the recording and it affects my judgment in such a way that sometimes these repairs don't go exactly the way that they should one thing that i should have checked on this before ultrasonic cleaning i mean you can see we've got balls swelled here we've got a little what looks like maybe a ball i'm not sure if that's a ball or not but we've just got balls swelled out over the all over the place now these boards whenever you heat them up hot with this rubbery overfill over the components these components will often times become separated so before ultrasonic cleaning this i really i think that one's moving i really should have peeled this stuff off of here and looked at it real good before i do anything else i'm going to go ahead and pop it into a housing make sure it still boots with no image and then we'll go back and reevaluate things test screen connecting up so we've got power button test screen and now we're going to hook up the power supply and now we're going to press the button to boot one two three boot we are drawing 80 milliamps oh we got just brief image did you see that the image just briefly flashed and then went off that is exactly what the customer said that this phone was doing it would just get image for a little bit and then it wouldn't get image again until it was turned off for a while and then turned back on he felt like something was heating up that was causing it to not get image so oh look here we've got image back again oh no more image see all this i bet you couldn't see that image come on for just a moment and then it goes off right i'm hitting the button to turn it off turn it on boy something is hanging by a thread so this phone is actually working with image now but i can't send it back this way because i know that it's not going to work again i've seen the image come on go off come on go off like something is just barely hanging on and i think i might know what it may be all right folks i think the problem here may have actually been what should have been obvious to me you know other than the ball squeezage everywhere all over this entire board i guess i should be more fair to myself i did go through in diode mode i checked all of the pins but this phone has an intermittent connection somewhere i really should have checked these components here because i think i see one moving already any component that's covered in this stuff when the board's heated up to the point where the solder melts these components can pretty easily become detached so i'm not seeing anything immediately obvious that it's moving i expected components to begin falling off by now that's usually what they do huh so maybe it wasn't such a simple overlooked issue here let's just keep carving at it so nothing loose yet these are all soldered down crazy yeah no big deal here i feel like most everything over here is going to be for on the other connector is probably going to be for touch not too much going on here these are all staying where they should be i've actually smudged up the solder on a couple of them still doesn't look near as bad as the half as the rest of the board yeah nothing coming loose here these are all staying down now how about over here where we had this one sort of peeking through the rubbery coating that looks to me like it was done with somebody's pry tool not actually a ball squeezing there's nothing coming loose here these are all soldered i'm not going to keep picking at this all right well it's not the components along the display connector uh let's have a look back down at the bottom side of the board straight to the old chestnut area i wonder what the odds are of us having a corroded connection under the chestnut icr probably not near as high as the odds of having a problem with the reball on the cpu let's have a look at that reball now that we got the flux cleaned off oh yeah it's beautiful work i feel like a couple of the balls maybe stretched a little bit like it had solidified after being moved just a hair but the reball actually looks it looks really good aside from having so much heat that it squeezed heat out around everything else on the board i think i may go ahead and just put another chestnut i see on it there are actually probably a hundred things that could cause this thing to have an intermittent image i would say there's a higher probability of it actually being a connection under the cpu however the cpu reball on this looks really good aside from balls squeezing out all over the place i'm going to go ahead and try to put a replacement chestnut i see on here and see if it may just be a failing driver for those of you that don't know the chestnut i see is the little chip that produces power for the display and we're going to replace it let's grab us a donor board now i know that this ic looks like it might have like you know some heating or something on the side of it but i can assure you it is a good ic because this is a 100 confirmed working donor board until i start stealing components off of it i'm really really thankful that a lot of these chips are available on several different boards so we don't have to have an iphone 10r board to steal this off of i used to have tons of these in stock but i hardly ever use a chestnut ic anymore so it doesn't make much sense for me to keep them in stock we'll just move that little cap out of the way don't need that there anyway and now the board's pretty well up to temp so we'll just swipe this right up off of there i like to pick up the board by the chip and then let the board fall out from under it this allows removing of ics with the very minimal heating as possible and is most always a clean lift all right without skipping a beat we'll move this right on over to reballing station v here now for smaller ics like this i just do them directly on the bench but when i get into larger ics like nand and stuff i do those on a paper towel all right so we've got a decent amount of flux oh really really it's just beautiful all right this is 99.9 isopropyl alcohol i purchased this on amazon clean this right on up now i like to try to get it to stay stuck to the table because the chip quick flux i'm using it will hold it down real good and this saves it from sliding around while i'm cleaning it see it it's nice and glued to the table marvelous we'll take us a stencil here and we're going to put some nice shiny new balls on it all right here we go let's smear us some paste down in here i'm going to try to just use the dry paste i've got on my blade yeah there we go it's not so dry on this phone although hesitant i am going to try to send it back working and able to start up so that they can see what's on it and also be able to run a backup i think it'll survive i mean it's a phone that they've been using amazingly enough right all right let's pop our stencil up off of here come on chip should stay on the table there we go and now we're going to give it one last nice floating there we are still got some straggling beads we'll heat it that's smart there we go all right and there we have a nicely re-balled beautiful non-hairy symmetrical leaded balls chestnut i see okay back over to the customers board here is their not so crummy chestnut i see it used to look really bad now i always like to put a mark somewhere on the board like i'm gonna do right here that little line i just put on the board for me that's going to represent pin one for this chestnut i see and now we're going to go ahead and yank this puppy off the board i'm just going to start warming the whole entire board up lord knows we don't have to worry about floating the cpu now do we although they probably use some lower melting alloy on it so we'll still want to be careful curious to see what this looks like underneath that actually did not look too bad i think there might be maybe one pad there that could have been detached there's definitely fuzz under it weird all right we'll kick that aside while the board is still hot we're going to apply some flux and scrub off these pads and get them ready to receive our nice shiny balls gonna need a little more flux than that aren't we nothing like cleaning them off real good and spotless and then squirting flux all over them all right that looks good enough for me now let's grab our replacement i see that i have laid here on the bench right there biggin and i can just see where our pin one marker is that's good so tiny little bit of flux although i probably didn't need to add any i'm just really picky guys i don't like what i'm seeing here there is a tiny little bit of solder there we go much better all right let's set this little ic down in here about like that there we go it should go about right there okay the chip quick flux now has it locked in place now we're going to heat it up and get it melted into place we should see it settle right on down in there all right so i was a little farther off than what i thought all right little nudge and it is on the board from here i'm going to let it cool off a little bit and then we're going to give it one more test run so with this one it's going to be a little bit difficult to tell exactly when it is fixed because it's an intermittent problem so once i see that it powers up and it has image on the screen i have to leave this phone running for a while and periodically come back to it and make sure it behaves consistently we'll connect the dock flex and connect the battery now we're just going to use a standard charger and put this thing through a series of tests because i believe it's going to have image now this is what i get for assuming we're drawing 800 milliamps of charging current one amp of charging current it is booted but still has no image i just heard the charge connect tone so just now we either broke image or we didn't make any difference at all test screen out of the way power button and take the board back out of it i'm going to look and see and make dang sure i line chestnut up properly looks good mmm boy what a strange problem okay the board's still kind of a little bit warm this customer said that they had to leave it sit until the board was absolutely cold before they could get it to get image again and then even then it was just briefly this one's going to be a mystery is it going to be a coil more likely going to be something to do with this cpu reball unless somebody rebuild the cpu to fix image that would be crazy well guys it is about oh it's late in the evening and it's time for me to take a break from this workbench i have been here for many many many hours so i'm going to put this one aside and i'm going to be coming back to it in the morning so i came back to this today determined to get it working i took the chestnut ic back off the board i took a bunch of diode mode readings under the ic i really couldn't find anything out of whack so i put another chestnut i see on the board i verified that 5v7 was present but this phone still did not get an image so i had pretty well decided that this was going to be a cpu level issue and this phone would likely need the cpu taken off of it rebald and put back on which would actually be much easier since somebody's already done it once here's this phone we have working image we still have working image i've had working image now for a long time let me show you what i did to get image working on this phone i decided that before doing anything as crazy as pulling the cpu off and reballing it it would be worthwhile to just go ahead and give it a gentle re-float so what i did was apply just as small amount of flux as i could to be sure that it flowed through and out the other side you don't want like a whole lot of flux because a bunch of bubbling and stuff can actually shift balls out of place and you want this process to be pretty gentle so this was actually a little more flux than i was comfortable with but i was watching the other side of the cpu to be sure whenever the flux would come out the other side so that i knew that the whole thing was fluxed and then i proceeded to gently warm this thing up with hot air i've got the hot air set on 350 degrees c with an airflow of 40 and i just warmed this thing up very gently and i watched the components along the side of the cpu uh checking with my tweezers to see whenever those components melted to use that is like a gauge so that i would know whenever you know the rest of the balls under the cpu melted now i apologize but as this warms up it is laying directly on my mat so the mat as it heats up is actually swelling and the board raises up some and sort of puts it out of focus but i really just want to show you what i did i re-hotted the cpu so we heat this thing up good and hot and once i'm confident that it is floated i remove the heat and gradually let it cool down so success no no no no no no not quite after i did this to this board whenever i connected the dc power supply it would instantly draw two amps of current and there was a short somewhere so my hot air caused a short somewhere so from there i flipped over to thermal imaging and with thermal imaging i could see that u6150 was producing a hot spot as soon as the power was connected so obviously there was likely something shorted under u6150 and if we look at the boardview you can see my heating took place from this side of the board and u6150 was right here and also u6150 was completely filled with underfill and that's likely where i had created a short so i spent some time picking around and clicking on balls and pads here and and tried to figure out exactly you know where things were going and it to me it looked like there was a vdd boost short because i could actually i would get a direct short to ground on vdd boost the real strange thing is that after i checked it once or twice the short actually went away but then the phone would only draw 80 milliamps 300 off 80 milliamps 300 off so i'm like i killed this phone i killed this phone so i went ahead and i removed u6150 from the board and that's where we're at right now so refloating the cpu completely fixed the image problem on this phone it is working and i have not had a single time where it wouldn't get image since i did that although i have told them that this thing is very likely not going to be fully functional i'm still not going to leave u6150 off the board so against my better judgment i'm going to go ahead and put that back on the board and then we're going to call this one fixed so under this ic you can see how we've got this flattened solder right here when i pulled this ic off the board where the ic sat was just completely flat with that it almost looked like we had exposed ground plane or something but now i believe that that is actually solder and we're going to find out right now because we're going to re-ball this ic let's add a little bit of flux and i believe that little bit is going to melt yep that's what it was so this had um actually made like a flat plane of solder from my hot air isn't that something somebody like hot aired the total snot out of this board and i come along and gently refloat the cpu one time and cause a short let's get this cleaned up get some nice shiny new balls on it get it back in the phone and then watch this thing boot without image i'll lose my mind now i don't think i have a stencil for this so we're just going to wing it it's probably similar to something else i got that looks about right yeah we'll use that it's probably the same as like a backlight driver or something let's get us some paste in here and my paste is getting a little dry it's actually getting a lot dry we'll use it anyway oh yeah baby all right let's gradually start warming this up a little more gradual than that well it appears dry until you start to heat it up okay here we go i see some meltage i'll do this real slow and voila shiny new balls well semi-shiny we're not going to be picky on this one give this one last float and there we have it looks like there might be a little bit of gunk in there on that one but we're going to leave it okay set this aside yeah i know i should just quit while i'm ahead but i am going to go ahead and put this chip back on the board so we'll warm this up a little bit add some flux way too much flux holy mackerel and let's get this thing back on the board oh boy i can't tell where pin one is we're gonna have to scrub that a little bit too much flux on the ic oh there it is there's my dot showing okay here we go let the chip go we're starting to settle down on there and that is on all right let's uh let the board cool off and see if this thing still gets an image and then i will be able to sleep at night i just you know i told him that most likely won't be fully functional i don't want to do anything that i know is going to make it absolutely not fully functional that icu 6150 that is the gecko i see honestly i don't know exactly what it does so if you would like to let me know in the comments below i would appreciate it okay so with that back on the board i'm going to push the button to boot 80 milliamps 130 apple logo so we didn't break anything passcode screen blank light up blank light up we're going to be good to go all right i've got this phone fully reassembled we still have working image we are up to 40 charged now i am absolutely curious to see if baseband is working i didn't look under that bottom shield but uh we have working baseband seriously and is wi-fi working we have working wi-fi ah sort of unbelievable now i do have to say that what i did in this video with refloating the cpu please please please do not do that unless all of the under fill has already been carved out from under it and it is a prior cpu reball if you try to do that to a factory cpu you will absolutely positively kill the phone and then it will definitely need a cpu reball so that is going to be it for this one guys this phone is ready to go back and this will be a happy customer and also i have a local backup in case for any reason they get the phone back and it doesn't turn on so that is it for now everybody i'll see you in the next one have a good day

Channel: STS Telecom

Views: 1,003,712

Rating: 4.854825 out of 5

Keywords: electronics, repair, shop, iphone, logic, board, microscope, microsoldering, pcb, hot, air, smd, hakko, phone, iphone xr, xr, no image, cpu reball

Id: xLr0f92xYTw

Length: 59min 54sec (3594 seconds)

Published: Fri Dec 25 2020