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You are here: MacNN Forums > Hardware - Troubleshooting and Discussion > Mac Notebooks > Macbook Air Early 2015, keep getting USB power warnings

Macbook Air Early 2015, keep getting USB power warnings
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MacNNFamous
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Oct 6, 2021, 11:38 PM
 
I was given a 2015 Macbook Air that didn't work, battery was wonked, charger dead. New charger, new battery, runs great, but I CONSTANTLY get "usb accessories disabled, unplug the acc using too much power to renable USB devices", which, is great, but there is nothing plugged into the laptop, so none of the USB ports work.

Ideas?
     
reader50
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Oct 6, 2021, 11:47 PM
 
Some internal components are on the USB. Keyboard, trackpad, camera, perhaps even the microphone. Have any of those stopped working?

Check your USB tree in System Profiler, see if it can narrow down which buss is down, and what all is on it.
     
MacNNFamous  (op)
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Oct 7, 2021, 01:55 PM
 
Keyboard, trackpad, camera, mic all work fine.

System Info says :

USB 3.0 Bus

Internal memory card reader
Current available 900mA
current required 896mA

BRCM20792 Hub
Current available 500
current required 94

Seems to all be working okay, just getting this pop up all the time.
     
Spheric Harlot
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Oct 7, 2021, 02:28 PM
 
Originally Posted by MacNNFamous View Post
Internal memory card reader
Current available 900mA
current required 896mA
Uh, there is no way this is going to be performing any read/write whatsoever on 4 mA overhead.
     
reader50
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Oct 7, 2021, 04:27 PM
 
Another thought. Use a light and magnifying glass on your USB ports. See if there's any foreign substance shorting across two traces. Might be worth examining the logic board too, for liquid stains around the USB ports. Something with enough carbon content to conduct some milliamps.
     
ghporter
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Oct 7, 2021, 04:42 PM
 
A dry toothbrush can get into USB ports pretty well. Even if you don’t see anything there, scrubbing at the ports isn’t a bad idea. Dust and hair (not just pet hair) accumulate in odd places like exposed ports.

Glenn -----OTR/L, MOT, Tx
     
   
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