820-3115 A1278 Macbook Pro not turning on logic board repair

all right today we have in a 1278 MacBook they say 1278 MacBook has no power let's open up this MacBook and figure out what's going on with it it's another MacBook that's been chosen at random so this MacBook is not turning on this is an ancient 8 to 0 - 3115 board dual core Ivy Bridge CPU so we're gonna now we have a light in the charger which means our pp 3 before 2 is present as can be seen here but as our pp bus present it is is our pp 5vs5 present it appears to be now the next question is pp 5 es 3 present and it's not VP 5 es 3 is not present hmm 155 es 3 is a short to ground it's always possible PP 5 es 3 is a short circuit to ground which to be keeping you from working and look it does have a short circuit to ground that's keeping it from working so we did here as we started going throughout the main power rails went through our pp bus g3 hotter pp 3 before 2 PP 5 vs 5 and then we went to PP 5 es 3 so if I open up the schematic and the board view for this board you'll be able to get an idea of what it is that I was looking at when I was looking at these these lovely things here so if I open up the schematic in the board view and I go to page 7 on this one you're going to see that we have a list of rails and I was measuring them one by one by one so we checked for our pp bus g3 huh it says over here supposed to be twelve point eight it was twelve point six close enough we checked pp 3 v4 - we take the voltage er there it was three point three close enough PP 5 es 5 we check for that it was where it's supposed to be then we checked for PP 5 es 3 PP 5 es 3 is gonna show up on this capacitor over here and it wasn't showing up so then what we did is we tried to figure out if we had a short to ground so we did I just went to that cup area - that capacitor I have no power plugged into the board as you can see here point 4 ohm short to ground and I'm at using resistance mode so that means that there is a short circuit of ground we're gonna have to find in this MacBook so I'm just gonna take this MacBook out of the case and we are going to get started troubleshooting and figuring out what it is that is shorting our power rail to ground you all excited folks hope you're all excited that we're gonna fix yet another MacBook cuz that's we do here on this channel as we fix MacBooks so we're gonna lower my powers apply down to five volts maybe even just one volt and output that into where I think the short circuit is according the somatic and board view PP 5 vs 3 is right here [Music] all right we're using five amps at 1.9 volt so this is a short that should be fairly obvious to fine as you all know I'm in the front of the store not the back of the store and the thermal camera is in the back of the store and so that means that I would have to walk to the back of the store in order to use the thermal camera to find shorts and that is absolutely not worth the proposition look if I have to walk I have to do any sort of work of any kind not doing it not doing it so we're gonna try to find the short circuit using alcohol which I do have here in the front of the store and if I can find the short circuit using alcohol then I can show you how to do this without having to spend money on a thermal camera which i think is way too much money for this profession given how proficient one can be with alcohol okay so Tim Herman of TC RS circuit said that the short is most likely near the audio circuit and I want to show you just how high-quality the advice that you can get by going to TC RS circuit dot repair slash contact - us that's TC RS circuit dot repair slash contact - us is if you need free advice on how to fix your own motherboard if you take a look at this board and we take a look at the audio chip you'll notice that the melting is happening right by the audio IC which means that he was indeed correct Wow look at that imagine that this is the again the quality of free help that you will get from Tim Herrmann is utterly amazing look at that look at that Wow folks I'm telling you this kid is talented he knew what was wrong with my board what we're gonna do now is we're gonna remove that cap and let's just take a look at on the schematic and board view all waiting for my hot air to get up get heat it up so it looks like it's this cap over here which is a long TP 5 vs 3 c this.c 6213 that is on people has one leg on PP 5 vs 3 one leg on ground that capacitor is able to short circuit to ground if it fails is able to send all the 5 volts to ground so we're gonna remove that and then this is gonna work right again isn't it now is beautiful absolutely beautiful and we couldn't have done it without free help from 10 @ TC RS circuit dot repair slash contact - UPS don't delay contact em for free help on how to fix your board today this cap doesn't look bad either so it really would trick you look at that there's nothing you know there's no solder ball next to it there's no discoloration there's no slash on it or anything [Music] [Music] you didn't take a recipe all-nighter what am rest you crazy there are Mac books that need to be fixed there are many Mac books that need to be fixed so as we can see here look at that look at that look at that fan spin so you had a short-circuit I'm people 5 es 3 remove the short-circuit we found that short-circuit by injecting a volt into the board pouring alcohol on it and seeing what gets hot very high-tech methodology here we use it rossmann group but it does work it is fast that is efficient and it is cheap and above all it is easily replicable at home by people who do not have super expensive equipment which is what I'm trying to get across that you don't need to have the highest end setup to get stuff done just got to use your brain a little bit and if you use your brain you can make the fan spin that's all I want is to see that fan spin and if you can do that then you too can fix a macbook that's it for today and as always I hope you learned something with that we move on to the next macbook you do you have a Macbook that needs to be fixed come by our store which is open to the public in 186 first Avenue in Manhattan are you located outside of New York no problem send us a machine from anywhere in the world by going to our website and clicking on the mailbox or simply heading over to send your macbook comm that send your macbook comm will you be redirected to our mail and instructions page that includes the form and the directions on how to send us a Macbook for repair we have a live chat where you can speak with us about the repair that you need a phone number where a representative will pick up during our open hours and a contact form where you can contact us about repairs

Channel: Louis Rossmann

Views: 50,658

Keywords: macbook, logic board repair, 820-3115, PP5V_S3, pp5v_s3 missing, macbook logic board repair, dead logic board, no power, macbook pro, logic board, logic board repair training, logic board repair macbook, macbook logic board repair service

Id: oTHwxtpUUeE

Length: 7min 55sec (475 seconds)

Published: Tue Mar 12 2019