MacBook Air M1 A2337 820-02016 not booting, taking 5V 0.42A and 2.173W

[slimmy182]

Hello, a friend give me this M1 Mac Air, he said that it simply stop working. Apple preventive is replacing motherboard.

Model is MacBook Air M1 A2337, logic 820-02016, not booting, and taking 5V 0.42A and consuming 2.173W.

Once disassembled is very clean, no water damage at all. Visual ispection reveal no visible problem. Flir camera point to two hot point:

C81DC PP3V8_AON_VDDMAIN
And
Q5800

What should I test as next step?

Thank you very much!

[mon2]

That is a hard short so it should glow like a Christmas tree.

You do not need to solder the ground wire but ok if want to do this. We actually use normal meter probes and pulse the injection by touching for a sec and remove the probe. Dial up 3A if possible and touch the rail with this missing voltage with the red probe. This action should cause the hot spot on the board to be visible under the thermal camera.

[slimmy182]

Unfortunately I have not a power supply to sort out the short. Any suggest how to proceed?

[slimmy182]

News: Now I got 30V10A Power Supply. If this could help

[mon2]

Carefully measure the voltage to ground of PPBUS_AON @ F5200 - check both sides of this fuse with the power adapter connected.

[slimmy182]

Cvoltage to ground of PPBUS_AON @ F5200

5.65V both sides

[mon2]

What is the voltage to ground of PP3V8_AON ?

[slimmy182]

voltage to ground of PP3V8_AON

C5887
1 PP3V8_AON_VDDMAIN 0.19V. This line has no resistence to ground, shorted, 0 Ohms
2 GND

[mon2]

Can you confirm the meter scale? Or share a pic of the meter face. If truly 0 ohms, you have a shorted component on this rail which will require the use of your power supply Suggest to dial up 0v8 -> confirm with your meter that it is indeed under 1 volt.

Then with no power to the board; apply this 0v8 power injection onto this rail. No battery, etc. but just this new fangled power supply you have. The current should spike due to the ultra low resistance and someone will heat up. Who is it? Hope it is a tantalum capacitor and split that puppy open. Watch for the smoke and/or heat signature. Use IPA (alcohol) if you need to and check where it evaporates the fastest.

[slimmy182]

Can you confirm the meter scale?.

here is my pic!

apply this 0v8 power injection onto this rail.

That would be the first time using a power supply to sort out a short, can't wait to start!

I need to solder the negative pole to the ground on the logic board, while the positive pole goes to the component related to the track I want to investigate, right? Do you have any advice on which component to choose? I'll make sure not to exceed 0v8 by checking with a multimeter. How many Amperes should I use? Fortunately, I have a phone with a FLIR camera; I'll try that, and if it doesn't work, I'll use IPA (alcohol)."

[mon2]

Shift the meter to 20k ohms and measure again to check the resistance to ground.

[slimmy182]

Shift the meter to 20k ohms and measure again to check the resistance to ground.

Zero ohms. Also checked in 200k and 2000k, still 0

[mon2]

That is a hard short so it should glow like a Christmas tree.

You do not need to solder the ground wire but ok if want to do this. We actually use normal meter probes and pulse the injection by touching for a sec and remove the probe. Dial up 3A if possible and touch the rail with this missing voltage with the red probe. This action should cause the hot spot on the board to be visible under the thermal camera.

[slimmy182]

That is a hard short so it should glow like a Christmas tree.

It should, and it happened!

It was C81DC , the same that was getting hot in my first post. Replaced and now the Mac is working pretty good


Thanks a lot mon2 for your valuable support, as always. I'm truly glad to have resolved this issue and learned to use a new tool. I owe you a beer anytime!"

[mon2]

Awesome! Well done. Will settle for one of your tasty pizzas. Ironically purchased a number of imported pasta sauces (Arrabbiata, basil) from Italy along with Italian spices from a local gourmet store last night. Junior loved it and dove into the stash right away. May invest into a wood fired oven one day.

[slimmy182]

the perfect pizza secret is the oven with stone base and good waterfoe the doug! But above All, italian love of course. If tou have any special whishes let me know, and i'll be happy ship it to you.