MacBook Pro Doesn't Charge, Looking at MagSafe #405

Come on now! Apple fuses don't, just break down! They're Apple fuses! Come on Graham!!! Lmbo

Have you tried a different genuine charger to check if there is an issue with the charger?

Good to see u Grahm!

My 2012 Macbook Pro does the same thing; works on Magsafe to USB C but not on real Magsafe. Thanks for the look in to it.

Did you check the fuse again after using a charger? Great videos Graham!

I clean my MacBook at ultrasonic, after that he get so slow....
I hope can make videos and teach us what can be the problem ❤

I'm surprised that you didn't suspect about C7012 or D7010, especially the capacitor, any reason to not check those? I cant see any other part of the circuit giving that kind of problem, but im a newbie to that kind of repairs

Judgeing from the look of the wires at the charger ware it connects to the laptop I think the charger is at fault if the Aftermarket charger is working and the OEM charger isn't that is a no brainer it is the OEM charger .

worth checking that zener for short?

My theory is that resistor is not connected directly to the ground plane. It was easy to solder that one and after laptop connected to power will create bigger resistance than 68k resistor what we can see on video megaohms . This is only way you can make bigger resistance is to disconnect that resistor from ground plane 😊 so laptop will bring green light recon that something is nok and disconnect resistor, after discharge it will come back to low resistance. Newer repaired single laptop board but this one seams legit for me. And yes on drawing it was direct connection to ground. And yes I love your video and my wife hates your face hair 😂 I love it as well ❤😅😂 nice job

Will the genuine charger stop if the resistance is too high, maybe the charging port is adding resistance?

Contact Louis Rossman in New York USA. I know of no-one else who may know more than he will. Good Luck.

Technicians use chipmunks to test laptops?

Issue is likely Q7180. Well known for leakage from a defective in rush limiter. It interferes with the charger load detection. Try replacing this chip. Had this issue happen to me a few times now.

Too late now, but a suggestion would have been to measure the overall current (when the fuse disappeared during resistor replacement, ho, ho) and compare that with another MacBook, if you have one. I know nothing about MacBooks or anything else really but the SSD comment piqued my interest. Pure guesswork on my part but perhaps the original charger may not have enough wattage for any extras (Apple chargers seem to very finicky in this regard).

What about if it charges when it is powered down, but wont charge properly when booted up? The Magsafe just shows a flickering green light and it doesnt appear to charge.....? :-) I've got one of these as well, one of the 2.9Ghz I5 Dual Core ones.....

I wonder if in future it’s worth checking the voltage that at the pin and compare it to what it should be. May be able to change the value of the resistor to create the desired voltage. I think it’s supposed to be 1.8v or something, can’t remember.

Inrush current too high when the genuine charger powers up, and it probably has an internal protection circuit that shut it down, while the "fake" usb charger have a higher current rating (or is more tolerant to overcurrent) and is not affected. That would also explain the blown fuse.
Would be usefull to have a current probe hooked to a scope to check that.

Thank you for sharing ! Very interesting

new battery old one is pooched ive had the sAME PROBLEM ON OLD MACS IF YOU HOLD THE POWER ON while plugging in mag safe it will boot

Thank you.

SYS_ONEWIRE et and ADAPTER SENSE must be ok too, to obtain the good voltage. The zener diode is like a regulator, when you apply more than it's voltage, the diode become conducting, to obtain 6.8v on DCIN_ISOL_GATE.

Nice video Graham.
What microscope do you use? Thank you very much!

maybe there is an issue within the geniune charger ?!!!!!

Your accent is distinctively more pleasant in this video. Thanks for sharing.

— Measuring high resistance to ground on PPDCIN_G3H just after unplugging the DC-in connector is expected as the power rail is still charged.
— The zener diode at D7010 is part of the bias circuit for the transistor, as it is a P-channel MOSFET it needs a negative Vgs to turn on, so when the voltage is below 6.8V the zener doesn't pass any current so Vgs stays at 0V. But when the voltage is above 6.8V (i.e., the power brick got out of "sleep"), the zener diode starts passing current and the voltage is effectively clamped to 6.8V as it is dropped through R7010, and therefore the voltage on the gate of the MOSFET is lower than the source (relative to ground, so negative Vgs) so the MOSFET can turn on.
— 1-Wire circuit is unrelated to the problem at hand, even with a blown 1-Wire circuit the Apple power brick would still deliver 14V-20V, but of course there would be no green light. Also since the non-genuine power brick has green light and charges the battery, the 1-Wire circuit is most likely working fine.
— Working only with non-genuine AC power brick is also typical of a DC-in MOSFET problem (as @cadan8258 also pointed out in the comments). It can be a leaky MOSFET (most common), but also something wrong with the gate drive, like the resistors or even the charger IC.
— The DC-in MOSFET issue might also explain why the fuse blew, the DC-in MOSFETs also act as an inrush current limiter and a reverse discharge protection, so something wrong there might overstress the fuse.
— As a side note, the 820-4924 board won't turn on from a non-genuine Apple Magsafe2 power brick (or rather cable, since it's the 1-Wire IC in the tip that causes this specific issue) if the battery is not plugged in or dead.

There are some random info about the Magsafe "sleep" behaviour on LogiWiki, page is titled "Magsafe Sleep Mode".

Inrush or actual current is too high and shutting off the genuine charger. Also somewhat supported by the genuine flashing the green light, then shutting off.
This also blew a fuse and fuses don't just fail, so something is going on. (obviously)

Just to let you know, iron heat applied to a single solder join of any MLCC will or can cause undetected cracks inside the ceramic capacitor and lead to short circuit after a while operating because of DC voltage on it forcing ionic movement along the crack until low ohmig bridge happens!

so triggered by your lack of si prefix understanding. nooooo not milliohms... 68kOhms-67.5kOhms != milliohms!!!

Not only that, 67.5kohm, is within the 1% spec listed 68k *.01=> +/- 680ohms, or 67320-68680ohms. (before you even consider accuracy of your meter... )

Thank you for sharing this kind of things

Can you put the link for bought the HDMI test ? Thanks

I've used a few YT vids for Macbook repairs but Paul Daniels and Louis Rossmann have been my go to more often than not. I avoid anything Apple nowadays as parts are often difficult to get unless you buy a donor board and repairability has got worse and worse over a 20 year period. I love working on the old imacs though, they're great to fault find and repair once you get into them.

thank you very intersting on how it all works thanks again

I think you would get a better result if you follow Mr. Solderfix and tack the first end using just a small amount of solder on the iron, then solder the other end properly, then finish the first end.

How do I get boardview files

Hi, do you also carry out revisions or repairs of motherboards on commission?

Were you get the schematic?

Hi thx for video I have a MacBook 16’ 2023 I let him in sleep mode some days after I want to charge it that not work no light in MagSafe and nothing happens u think the problem is the battery or something else ? Thx for your answer

Thanks for the video... first time I've ever heard such in-depth explanation on how MacBook charging works

You just saved me a lot of money man!! Thank you!!!!

Working theory about this one is an issue with the SMC's OneWire line. I should've looked at the U7000 area, which is the chip that goes between the SMC and adaptor. However, given that a fake charger gives a green light, it seems unlikely that there's a problem with U7000. The next step back is the SMC itself having a busted OneWire line.