Uploads from Joey Does Tech

I'm a noob when it comes to laptop electronic repair. My main focus is usually gaming consoles and it's been roughly about a year since I've done a Joey Learns episode. What is that? Where I do it pretty much exactly that and I throw myself in the deep end. I work on a device that I'm not usually too comfortable with and see if I can get it to work. I visited some friends at a repair shop and they had a device that had been sat around for a very long time. They weren't able to fix it and the customer said that the shop could have the device for spares and repair. I've then taken the responsibility of trying to fix said device. It's a laptop that simply has no power. Buckle up because I'm probably going to say 10,000 things wrong. And if you do want to share any experience or knowledge down below in the comments, feel free. Without further ado, let's crack on. I'm going to plug in this which works. I think this is 100 watt power delivery for 100 watt. Here we go. So, 100 watt power delivery and plug that in there. And now I need to see what the situation is. Okay, let's see what draw we get. First off, do I have the correct connector? Oh, would you look at that? Yes. Okay, that's really, really good because I didn't know if I had the correct one and I do. So, let me pull up the ammeter. So, we've got the software now on the screen up. Oh, that's bumping up. What's that bumping up to? 6 and 12 amps. That's a big short, is it not? 6 and 12 amps. I mean, it's trying to do something. Is that not a lot? That's a lot. I don't know what it's meant to draw, but I'm pretty sure laptops draw around about the uh the 3 to five. What is this? T6. Now, I'm going to use my Sessimo here, and you might be like, "What? This has so many scratches on already. I don't think it necessarily matters." The goal here is to obviously just get it up and running, but it has a lot of scratches already. Like the chassis, it's just not in a good condition. Here we go. Okay. Right. So, it looks like everything's been put back together nicely. Let's see if I can measure some voltage and see what the situation is. It looks like maybe that's been soldered down there. Again, this is from a repair shop. Let's see what's going on down here. That is definitely definitely liquido damage because you can tell by the uh caps at the end. Like here, see that? And yeah, yeah, yeah. Okay. I didn't see an SSD. Could be soldered, but there is in fact no SSD here. You're right. And it's just NVME. Nice. Yeah, there's definitely some sort of corrosion going on. All right, let me uh I'm going to plug the amter in. Oh, there's a coil missing here. And the battery is not plugged in. God, it gave me a difficult one. Hey. All right, I'll rate it. I rate it. I rate it. Battery is definitely not plugged in to the point of how it should be. Let's plug her in. All right, battery now plugged in. But definitely a coil missing here, I think. Hey, mega ohms there. Kilhms here, but no short. No short. So ground this side. No short here. This where we're going to have the main power coming in. Right. Is that fuse? It's PF. Yeah, definitely some sort of liquid ingress. Look, you can see. Definitely would have had a trip in the ultrasonic. Let me just see what I draw now without that coil. Have to bear that in mind. It's plugged into the battery now. It's not making a difference. 6 and 12 amps. There's nothing to do with the battery because it's the main power rail and the battery is unplugged. I get no difference. I wonder if I need something here. What I might do is take the battery out and to put a coil and see what happens. See if I get a change in the reading. It's a really tight compact area for this battery. I'll tell you that. Obviously don't want to bend the battery. Uh yeah, I don't know if it's going to be missing anything else. I'm kind of thinking just take out the motherboard and attach the battery separately and see and just start working on it that way. So I therefore I can also see underneath as well. You know, 6.5 might be the max. Yeah, I I would also I could try um I could try just quick to using the thermal cam and see if anything heats up with that six drawer cuz something's going to be going pop. Something's definitely going to be receiving a lot of heat with a six 6 and 12 amp draw. So, let me see that quick. Can at least I could start working around that area. Issue being as well is that if I just go ahead and put a coil here, it might make something more dangerous. Let's try and find it without putting that coil back. Actually, I think that's a good shot. I got that there. Is it that coil getting hot or is it the charging IC? The good thing is that I've got a component down here that's getting hot. Looks like a diode and I've also got this chip getting hot as well. So this chip getting hot and this what looks to be diode is a P 0103 but let me just have a look and see what the situation is now. It could be that it is simply meant to get hot in those areas, you know. But let me show you the components that are getting hot. I wish I knew if it had been put on the right way as well cuz we don't know that. But that looks like it's definitely had solder or had a job of solder done to it. And then another one is down here getting a bit warm and spicy. And I think that's that looks like what he's tried to do is solder a wire to it and give it some voltage. That's what it looks like to me. A solder ball there. Is that a solder ball or is that just I think that's a pad like a test pad or something. I'm assuming this is on the right way because we have the line here and the lines here. I'm assuming that's the right way. Line here. Lines here. DC voltage. Can you see that drop? And across here is one volt. It's just it's on Okay. So, it's on both rails and there's no inductor here. It's doing something. Why is that voltage so erratic? Voltage of the main power rail. I'm going to measure on that side of the diode where I got 19 volts. It's all over the place. Kiloohms, 16 kiloohms. Don't know if that's main power rail though. Just cuz it's 20 volts doesn't mean it's main power rail. Whereas on this side of where we get 20 volts, we get 14 megga. So, resistance seems to be okay on the main power rail. And I'm assuming that would be main power rail where that coil is. But why is the voltage all over the place? That's the question. And it could be anything. Why is the main power rail voltage all over the place? I wonder if I take the board out if I still get that reading. Let's see what happens when we just get the board ready. Still hear it clicking. Let me see if there's something else on the other side of this board that's getting hot. Cuz this side we've got a couple of areas of contention. So, we've got this chip. No, we got this di That's a diode, by the way. That's a diode. Sorry, that's a transistor. So, I've got a transistor here, which is bad. I've then got this MOSFET, which is bad. I say bad, it's it's 30°. And I've got this diode, which is 31 degrees. Those are the three main areas. Let me turn around. Could be the uh MOSFET. Makes sense as to why the voltage is jumping around as much as it is. What about the back side? Oh, whoa, whoa, whoa. We get a 42 degree MOSFET on the back. Whoa, whoa, whoa, whoa, whoa. 43, 43, 44, 43. What's that FET doing? Cuz that's a lot. That's a lot more than the others. Do we have a bingo? Why is this pulling 40°? 43 degrees. Not much. I I agree. But in comparison to everything else, it's hotter, right? So, what do I get? Drain to source. 21 ohms. That's low. Hey. Oh, you guys can't even see. I get 21 ohms. Gate to drain. That's not good, is it? Drain to source. Not gate. If I say gate to drain, I apologize. Uh, drain to source. 21 ohms is really low. How much resistance do I get on the gate? Kiloohms. That's fine. But the through of 21. Well, what about these FETs down here? Cuz these are the other ones that were getting hot. Oh, well that's shorted. Well, that's kiloohms. That's shorted. Don't tell me that's normal because if so, I'll give up everything I know about electronic repair. Inject one volt on the output of PQ 401. Uh output being this side, right? Zero amps. But I also get zero amps on this side. Oh, wait. I get no draw this side. No draw that side. Doesn't matter that those two pins are together. Could just be a short MOSFET. I shouldn't have continuity through a MOSFET, should I? So, let me turn that off. That is in an awful position as well, by the way. I think we can all agree it's not in a great position. I could go from underneath, right? Underneath would definitely be the safer bet, but they don't call they don't call me Risky Joe for no reason. Is it even on? I do want to measure this out of circuit. Yeah, it's shorted. That's a shorted MOSFET. So if I plug this in now without the FET that's plugged in. I mean to me that looks a lot more stable. Now granted I don't have the coil nor do I have that MOSFET on. Now if I go into DC voltage measure here 19 volts measure here nothing because obviously it ends right and there's 19 volts here or here there's 1.3 volts this side. So, this one, this is 1.3, but that might just be because I don't have the coil. I wonder if I plug the charger in now. I wonder if I plug the battery in whether the battery will charge or not without that MOSFET. I don't know if that's a main power rail MOSFET or whether it's a charging. Yeah, 0.02 is good. Yeah, I don't think I'm going to be able to I need to replace that MOSFET. Right. I just need a MOSFET now, but I don't I don't work on laptops, so I don't know if I'm going to have this MOSFET. Assuming it's the same as the one above it, right? Yeah. Where can I find that MOSFET? Am I I'm not going to be able to find that on the console, am I? These these two pins these three pins. If these three pins were bridged right here, it wouldn't matter because they're on the same rail. So you see this this rail, they're on the same rail. Same here. It's all on the same rail. So it doesn't matter if these two are bridged. If these were bridged, different story. Then I'm looking at this MOSFET. And that's different to that. And that's different to that. So the chances of having three different MOSFETs here is not realistic. I've got a MacBook board, but I don't think I'm going to have what I need on there. Lenovo 81 Bravo Delour laptop disassembly. You're you're telling me it's the same as this MOSFET here? this one and then when the other MOSFET comes, I'll simply just replace it and see if that fixes our issue. Good thing is uh our shorts gone supposedly. So when this was on the board, we had our issue and it was drawing like 6 amps whereas now that's not happening. So I do believe that this was our issue and I get a short through the MOSFET as you saw of uh zero ohms. So I think it was shorted to to ground on the inside or something. So I ordered some MOSFETs for this laptop. So, we get we get 15 volts, 21 milliamps, and uh we actually found out that we had a shorted MOSFET on this board. So, I purchased the MOSFET. I don't know if you remember on AliExpress, but I purchased the MOSFETs and that they've now come. What I'm going to look at doing now is putting the MOSFET on and seeing if the laptop works. Can I just go ahead and put a like a PS5 coil here. Here we go. 7752. Yes. All right. So, very similar. That's why I need the 7752 part. Um I'm pretty sure pin one's going to be here. Wait, I should be able to tell again because if I just turn this around, that would make sense, J, wouldn't it? should be able to see from here. Yeah. Okay. So, pin one is top side. Cool. So, I can put the MOSFET there. Like I said about the PS5, I I think I'm just going to Now, this could be completely and utterly wrong. I think I'm just going to use a PS5 coil. I think it might be a little bit too big. I'm going to take it from the power rail. Is board plugged in? Absolutely not. No, no, no. That's just the cable that's plugged in. Let's go 450. Push to about 30%. Probably go with the soldering line for this, I imagine. Okay. Should we see what the situation is? I just want to make sure that I don't have a short here now because the short was gone. So, I'm in continuity mode. The short was gone when I removed the other uh MOSFET. You see? So, I'm in continu continuity mode right now. I get my words out. So, multimeter beeps. Measure here to here. No short. Out of interest. What do we have in resistance mode? Kiloohms here. Kiloohms here. Good. Okay. And then let me just measure the resistance on each side. Kiloohms. It's going to be the same this side because we don't have any we have a really really small path of resistance. Kiloohms. Okay. And here kiloohms. Kilhms. Right. Technically, I mean, I don't see a reason why this wouldn't work, but uh like I said, this was taken from a repair shop graveyard. So, there is every single possibility that they've done this and it didn't work before. So, they've done a bunch of other things and, you know, took additional components off that I can't see that are missing. There is that possibility as well, but I have had a glimpse over the board and it doesn't necessarily look like there are any other components missing from what I can tell. Wonder what hot air temp because the plastic was dead close to it. If you move the air, you're good. But it takes a lot of practice. That was 450 degrees CCelsius. But if you move it, you can you can do it pretty well. Three, two, one. Okay. So, we don't have the draw of it going up to 6 amps. So, what I was doing before is this was pulsing. So it would be zero and then it will go six amps down. It will go across. It goes six amps down. We go across 6 amps down. This is good. 100 milliamps. Take the 10 off that we have for the actual cable on the ammeter. So we're looking at about 85 milliamps. I don't know whether that's good or not. I have no idea. So now all I have to do is I guess put it back in the chassis or let me just connect the battery and see if we get anything from doing that. Logger for standby. Expect 10 milliamps or less. Let's see what happens to this. Okay, so that tells me it's not charging the battery and something else is at fault because I get the same draw without the battery hooked up. Let me just use my let me use my thermal cam and see if there's any bad heat spots for the 100 that I get. And then I can end up I can just like follow around voltage and do all those things. Yeah, it should be enough to produce the heat. I think it's going to be one of those transistors, you know. Whoa, that chip is instantly getting hot. Look at that. Okay, that's good because it's the only thing that's getting hot except for a Novatton chip as well. That is uh that's 4050° which is too much. It looks like some sort of power management IC chip which is good. Maybe like a BQ. Is it a BQ? Ah, I called it. So it's a charging it's a charging chip. Looks like it's been replaced before. Is that pin one? Yeah, I think it is because of the dent that we have. Are any of those bridge? Cuz it looks like it's been played with before. Could do with a little reflow but these all look fine. They're just about on. Let me give it a quick reflow. Not that that's going to change anything, but I'm pretty sure that is like a bog standard charging IC for a laptop. No. Want to try and get it to move in place on its own. That's why I'm being quite ruthless with it. Doesn't look like it's going to. I think it's still a little bit lopsided, but it's okay. It's not falling into place properly. So, I mean, as long as they're connected, the joints just look a lot better now. Just bugging it in quick. 21. Was it Wasn't this 90? Wasn't it 90? And the lead is 10. H. Yeah, I thought I swear that was just 90. I'll try with the battery. See if we have any change. I wonder if same chip is getting hot. I can't see because the battery is on it. But it was definitely doing 90 before I put the battery on there. Pretty sure I think it is. Now it's back up to 90. Now the question is, is it a faulty chip or is it something around the IC that's faulty? Let's have a look. Let me measure Let me measure uh some voltages and see if anything is quote unquote weird. So multimeter is going to go into voltage DC pin 28 6 volts. All right, mate. What? Check that first. What What was that? 25 26 25 26 27 28 Yeah, I get 6 volts. 0.01 volts here. Same here. 4.4 0.1 0.1 We get the 17 coming in. 17 here. So I get 17 17 0.06 on what looks to be pin 20 32. This one 5.5 volts on pin 30. I'm not going to have a BQ on any of those devices because they're not charging devices, right? Got a BQ on the Switch obviously, but it's not as big as that. It's a much smaller one. Buck boost battery, charge, controller, assistant, power monitor, and processor. Yeah. Well, let's just see what voltage I get here. It's back down to 21 now. Keeps changing. Hey, Ah, 0.032 0.05. Wait, so we're losing that 19. Where are we losing that 19? Cuz I'm sure that's meant to be 19. Wait there. Okay, so we have the 17. here. So, we lose it on this fat. So, I get the 17 here, nothing here. So, the voltage isn't going through on this gate. That's where I get the 3.7 on this gate. I get nothing. Oh, what are those solderables here? Look what Yeah. So, here. on the gate I'm getting nothing zero. Whereas here on the input side I'm getting 181 19 which is what's meant to be happening and I get 0.02 on the drain but the gate 0.0 something's happening there. 0.0 sorry 0.4 Yeah something's 18. Whoa. Now I'm getting 18 on the gate. And now I'm getting 18 hit. Wait, what? 18 here. Now I get zero here. So, wait, wait, wait, wait, wait, wait. I get 18 here. Now I get 18 on this side of the FET. 18 here. Nothing here. Let me take it out and put it back in and see what happens. Now, it's showing like 2728, but it looks like it's doing something now. It's doing like 2728, but it looks like it's doing something. So, let me plug in the battery. Oh my gosh, she's working. She's working. I think she's alive. I don't know. CPU doesn't feel hot. 2.5. That's good. I feel like I should put it. Hey. All right. Hold, hold, hold. Now I need to put this back in the chassis and see what's going on. No way it was going to be that resistor. Do you reckon that solder ball was shortening it that whole time? Do you reckon that's what it was? Well, not the whole time because obviously we had the bad MOSFET. Do you reckon that line there is a different is different to the resistor? It does look on a different path, doesn't it? So, this is 0.7. The resistor is 0.4. Wow. Wow. That's 0.7. This is 0.4. I wonder how long that was there for. That must have been there since I started working on it because the only thing I did was this area. And I don't think I would have flicked any solder over here. Nor when I pushed this down or refflowed it, would it have affected here? That resistor looks like it should go downwards. But yeah, is the resistor actually connected? Wait, I don't know. I don't think so. Wait, there's no pad there with that resistor, is there? Oh my gosh, you guys are right. That resistor is meant to go that resistor is meant to go to that pad. Wow. Now, this is in a really delicate area here. And this is the issue, isn't it? Cuz this is this is a donor board from a repair shop. So, uh and they didn't tell me what the situation was. I I said, "Have you got any?" And they said, "Yeah, take this one." Uh to be I have no one to blame but myself. Yeah, probably chasing the short and moved it. Agreed. Definitely goes to that pad. Hey, no, I'm going to go from underneath and just move it quick. Yeah, other side's fine. No plastic, nothing. So maybe that explains the whole gate situation cuz where's that where's that resistor connected to? The gate. So not only was this resistor not connected to the gate to allow some sort of pull up or pull down voltage, whatever it might be, it was also bridged to this little ball here, this little test point. How on earth? Wow. Great. By the way, bridger, great spot. There's no way I was spotting that. Let me just see what happens now. Yeah, the same. We have the same. So, it's doing like that. Probably looks a bit healthier now. Hey, it's a little bit all over the place. And then when I connect the battery, we should be okay. Are we still getting that big drawer? Yeah, I can feel components warming up. What's that big drawer there? What are these two big drawers? Do you think? Do you think that's it? Just like attempting to turn on or something. Three. Keep an eye up on here where we got the ammeter. Three, two, one. Wow. I mean, that's a healthy draw. There's a dip. What's going on my camera? That isn't healthy, is it not? It's a lot of amps. What is it meant to be? Yeah, I thought battery was charging as well. 3.25 amps. It says 3.25 amps on the back. 20 volts. 3.25 amps. I can I can hear a clicking. There's no light on the power button to indicate it's charging, but I don't know if there is another light somewhere. wouldn't pull three amps to charge, would it not? Something's clicking. Something's clicking. There's a screw there. It's still clicking, by the way. I can hear it clicking. It's a MOSFET making the clicking sound. Yeah, an audible an audible MOSFET. Things I've never heard of. It's faster now. What? I don't know what's going on. It's It's now It's now a different MOSFET. So, the one that I marked gold is here, but the one that's pulsing is now the one that is above the one that I replaced. You see that? I thought it was this one. Wait a minute. Let me put a battery in because I need to know. It's the whole It's It's the whole circuit. It's It's all of them. It's all of those MOSFETs. Why are they I mean, that looks really good, actually, in terms of being able to read them. Why are they all different? Should they all just be 7752s? So, we've got the 7752 here, 7752 here, then we've got a 16 GU, then we've got a 7401, a 7408, under the MOSFET you under the resistor you rotated. It looks like the pads could be bridged. You talking about here? I think they're meant to be bridged though, right? I changed this one with a new one that I bought. I changed this one and this one. I need to find out the original components. So, I've got 7752s now, so I can just replace. But 250 ohms through there. So, it looks like Are you telling me this was meant to be like that or is this shorted because of everything that's going on? Like, is that blown? Cuz that was that was kilohms, right? Before this was kiloohms whereas now we got 252 here. We got kiloohms here. Wait, we got kiloohms here as well. So we got kiloohms this side. So source drains kiloohms but through is nothing. Unless it's meant to be like that. The resistor is just a throughput acting as a fuse. Right. Doesn't connect to that inductor. It goes somewhere else on the board. Measuring do source to drain. Of course nothing other way. Nothing. Whereas this one climbing goes up to three 0.18. Check these ones. 0.18. I don't know what's going on with this. And it's getting a little bit difficult, isn't it? By diagnosis. Right, we've got this MOSFET which has been replaced. Just to recap, right, so this MOSFET has been replaced by myself with a 7752, which is what is meant to be, this one, 7752. So technically these are okay, but this was pulsing a second ago without the battery plugged in. Then if I go up, I've got this MOSFET, which looks like it's been soldered on. So I don't know the true value of this. And then we've got this MOSFET here and this MOSFET. This is a 7408. This is a 7401. Again, if you look at these, it looks like they've potentially been soldered. So I have no idea if these are like true to what they're meant to be or whether they're different. And because I've picked this up and it's a donor, I feel like there's maybe been a little bit too much done to it for me to carry on and try and diagnose this. If I knew if I knew the exact history of what was going on with this laptop, I think it would be a little bit better because I don't know the history. It's making it very difficult. It's been into before. Someone's attempted repair and it's been chucked in a donor pile and it's had corrosion damage. So, I don't think it's a good use case to be honest. I think I should uh put this one away and call it quits. So, I ended up doing exactly that. And now I've begun my donor board laptop pile. Everybody has to start somewhere. And I feel like this repair for me personally was just a little bit too complex. And given the scenario and situation of it being a donor board to begin with, then uh I think it makes sense to give up the ghost on this one. Unfortunately, any of the tools and equipment that I use today, I'll leave down below as an affiliation link so I get a bit of a kickback if you were to buy something from AliExpress or Amazon. Thank you very much for watching. If you did enjoy, hit the thumbs up button, subscribe to the channel if you're new around here. And as always, I shall see you in the next one.