With 1.7V Vcc Core, my Pentium 4 used to run a couple of games, toast the bread for my sandwich and heated the room as a complimentary.

There is no failure on your analysis,you have superb fault finding skills!

It's never the cpu... ...until it is

Sorry for the dead CPU, but it was a very interesting diagnostic follow through, thank you Graham!

Damn it Jim! I'm a doctor not a repair man!

Quite interesting to watch you work, and yes KZfaq, I definitely want to see more of Graham diagnostic services and repairs.

Another confirmation of a failed CPU is to lift the heat sink and check for a crack in the glass surface of the CPU.

Fan Spin! (to quote Louis Rossman of Rossman Repair Group) ... good that this Macbook still has a removable SSD instead of soldered Flash chips ...

I love how you work and how you explain every step to resolve the problem, you do super interesting videos! Thank you for sharing your videos, I am learning thanks to you!

Northridgefix has encountered the same problem and cursed how Apple can build such a piece of crap that is destroyed by a Dollar mosfet. His website and knowledge are incredible, I learn a lot watching him (and you too).

Thank you for your job, your yt channel has great educational value and you’re awesome at explaining things, it’s easy to understand even for non english native. Cheers

Very informative and descriptive. Keep it going and the good work. When I saw the fan spinning, hope came to mind but back of my mind I thought probably not. You were right all along once you made the probable diagnosis.

I watched about 2/3 of your LFC videos hehe. Thank you for them 😁😁

Thank you for your job I'm just learned something new.

Nice diagnostic explanation. Thanks a lot. Best regards, Nicolas

Graham you know your stuff great viewing and learning and I still never owned any Apple product and will continue that way

Great video once Again

Very interesting bit of detective work. Thanks.

Great work 👌

Great video bud very informative

Really super thanks

Great troubleshooting video

Thank you!

Great video! =)

I love your fix computer shows

Interesting and informative explanation on working on a Mac. Something to absorb for the future usually I don't work on macs.

Nice instructional video! That's why I like laptops with socketed cpu even if it's old cruddy core2 duo. dead cpu means just two second to swap in another spare el cheapo cpu.

Amazing logical board repair video step by step👌👌👌So low price PPBUS G3H also means a dead cpu, due to a PCH fault. Maybe if the initial reading was close to 8v, that would mean a fault in the integrated SMC. Anyway, your effort was amazing and thank you for sharing it with us

100-200ohms is very often the 1.05v PCH supply on these macbook boards, just for future reference. The PCH will sometimes visibly crack too when they get fried

27:17 Ooof 1.7 volts on the CPU Vcore , yep dead cpu now 💔💔

Thanks!

Interesting movie GRAHAM. we are waiting for more to come THANKS

thanks your a good teacher I really like your vids

Interesting video! Seems strange that Apple doesnt build in more protection besides that mosfet to prevent the CPU from getting cooked if it fails. Great you showed a fail as well! Looking forward to the next one, keep up the great work.

That was super interesting thanks

Thanks 👍

Great video! There's always things to learn in the failures. Definitely do more videos where you don't fix the problem. The diagnostic steps and thought process to come to the conclusion it's not repairable is just as valuable as the ones you repair. Out of curiosity what is the steps moving forward? Can the CPU be replaced with a donor? Can you order just the CPU? Do you need to replace the whole board? Thanks!

No Graham, there's a bad looking cap at ..... sorry, couldn't resist (ance) great vid

its always the PCH thats integrated to the CPU that fails.

Very good. Could you do a video going over how you check all the smd components how to tell all the bad. Thanks

When i had to find something on the board like burnt capacitors or anything like that, i use my phone cam in macro mode then a little zoom 🤣

Wouldn't it be easy to install a transient suppressor diode into the circuit where are voltage sensitive stuff installed? It would not cost much money for the factory. That way, those diodes would save CPU, GPU, RAM, and SSD chips from getting that overdriven with too much voltage.

''The CPU is going up in flames man'' 👍

Thanks

Board repair 👨‍🔧 Super man

I really appreciate sharing your knowledge. You have NO IDEA how this channel helped me through my LIFE. I'm literally making income using knowledge from your content. NEVER THOUGHT KZfaq WILL HELP ME RECOVER

thanks u

You can't save 'em all, but very interesting vid!

Ah this reminds me of dealing with a Dell Precision laptop that end up having liquid damage on the 3.3V always on power rail and shorted the high side MOSFET, and what would you know? SuperIO chip is stone dead when 19V blasted through it and gets mad hot every time the laptop gets power! (I can't just replace the SuperIO chip on those things as the BIOS image is inside and finding a replacement chip is already hard enough)

I must have magic fingers, because I can feel a 200 ohm to GND part lose it's chill with 1A running through it - lol -. I can't feel it with my right hand, but I can feel it with my left because the skin is thinner on the less used one.

Short to ground could mean the rail gets shorted and devices after that do no get overvoltage. However, that 1.7V doesn't look good. But it still might fixable if the issue is the buck converter driver IC or something in the surroundings. CPU Vcc lines are typically controlled and yes, it could mean CPU got crazy and asks for this insane amount of voltage or the voltage regulator is doing its job poorly and the CPU overheats and shuts down (not dead yet). I would give it some more tests regarding the high voltage on the rail. But yes, there's very real possibility, CPU got too much and is shorting the rail by itself and that really would be the end. I'd check the high side mosfets for shortages (which would lead to overvoltage on the relevant rails)

I wouldn’t say a complete fail you got a lot accomplished just the cpu is out of you’re control but you did get everything else working

Hello dear Adam I would like to know, what are the consequences when inadvertently placing the transistor in reverse? It happened on a 2018 macbook air, I put the Q3431 upside down

if both power rails are working correctly (not shorted), what are the next troubleshooting steps? Maybe you have a video on that?

ouch x3 and rip cpu

👍

Please be careful when "toothbrushing" the board like that ! You can easily knock off components, especially if they're corroded and the brush is hard - I screwed up a phone board this way and had to pay for it :))))

Proves you can have the super IO happy with all the rails and turn it on and fan spin but the CPU or GPU? is burnt out /shorted. wouldnt the circuitry detect that too and switch off as every time i have a shorted CPU, it gets hot drawing the amps and the PS switches off.

New name...... "Let's Unf*ck Computers"

Could measure voltage over the current sensing resistor. To sense current. This could confirm short.

Hi, i have an acer m3-581tg it won't turn on ... it has all the voltages for about 5 seconds and then it loses them. what could it be?

Sometimes it confuse me yet the computer work anyway with some low resistance reading only within the cpu domain

Is a replacement Ebay board too expensive? There seems to be a lot of them for sale.

Should name your channel eaglevisionIt

Cool video but the title was a bit of a spoiler! 😂 Is it me the only one that likes to discover things as they happen?

27:37 1.7 - 1.8v for Vcore on these is fine. Yes it's damned annoying when you are in an S0 state with fan spin but brain-dead CPU. Not often much chance of surviving shorted high side mosfets

It's an Apple, rotten to the (CPU) core!

Which board or model Year? anyone know? looks like 11" got it: --> A1466, 820-3437-B, 13" AIR, EARLY 2014?

Graham, how do you manually control the brio focus whilst capturing in OBS, do you have other software open or have you set up some form of hot key arrangement?

Where do you buy your schematics?

Is it not worth replacing the CPU? I know BGA is a pain, and requires special equipment which you may not have, but would it be worth doing if you had the equipment?

I watch a lot of your videos and have to ask why you chose not to look through the scope to visually look for burned chips? I"M a rookie and only repair for fun.I have meters and rework station but not the NICE magnifier on the stand ,but i still manage to fix about 70 % of laptops.Could you point us to where the schematics are found? and cost maybe?thanks you do teach good stuff just in a different manner.

I enjoy the troubleshooting and explanations, never worked on MAC. One question, other than not having one, why did you not replace the CPU or, can it not be done because of some insane APPLE reason...

21:40 maybe it's better to remove L7630 coil?

She's doneski, Steve. 1.7V vCore sounds like a FB issue to me. Had a GTX 580 kill itself over a bad FB circuitry; 0V on FB, it decided not to trip OVP or UVP and shoved 5,56V into the GPU

👍👍😎✌️

1.8v is normal vCore for the CPU on this generation of macbook boards btw

What is the most likely low resistance one can measure around the cpu?

Wouldn't you know, why the hard drive wouldn't show up in the BIOS? It used to work, and then suddenly did not load up Windows anymore.

But not as we know IT

So, I presume this means that the computer is just completely toast, buy a new one. Is it possible to still recover data if something like this happens? Also, I've always wondered what happens to these unfixable laptops. Does the customer often just give them to you and they become part of your donor stash?

Quick question: thought the CPU rail was a low resistance rail hence difficult to identify a short on it. Was this mosfet on a different rail?

can you change the CPU?

What would happen if u replaced the cpu would it work then ?

It's so sad... you channel grew and your uploads are so rare now :(

I just checked my laptop proccessor running at 1.319 volts.. at 3.6Ghz I think 1.7 volts won't instantly kill the cpu, but maybe it will shut down the laptop

Never the CPU until it is 😀😀😀😀😀😀😀😀😀😀😀😀😀

Hi,can you help me in getting this boardview please: lenovo ideapad y580 boardview You sent It's mainboard no. Lenovo Y580 compal LA-8002p Rev:1.0

So sad that they dont have a protection for cpu😢

You just need to get a new MacBook Air. Easy fix, 100%.

I'm not a tech, but I wonder why there is no safety circuit for this kind of fault, to prevent the cpu getting fried? I guess the answer would be like most apple products. They don't want it fixed, they want you to buy a new laptop.

Into the landfill it goes. I am glad Apple changed it's website so it looks like they are super green and really care about supporting broken machines instead of wanting to sell you the same crap year in year out.

1.7v vcore, that thing is dead

You Said PPBUS_G3_Hot, where is Rosman :D

hmm toth brush not a ggod tool dude as it will cause a static charge and can damage the electonics unless you have a brush that wont cause staitc build up

It's Apple.....

Hi Adam! did you accept repair my laptop for service?

+

There's a good chance thermal cam would still find the short, even at 200ohms. As long as you took the heatsink off the CPU

you are from the uk? why you just casually use german words xD kaputt schmutz spritzen