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iMacDragon

macrumors 68020
Original poster
Oct 18, 2008
2,434
767
UK
Is it s but on my laptop, or T2 managed charging generally I wonder.

When left plugged in but asleep my 2018 model 15" is making what I presume is the "I'm 100%" charged chime every few minutes on a somewhat random schedule whilst asleep and left plugged in.

it seems to happen about 3-4 times after first putting asleep over period of 5 minutes or so, before easing off, taking 5-10 minutes to next chime thereafter it seems.

I can't believe it's meant to do this as it's incredibly annoying, especially when I'm trying to sleep!

This happens on default power saving settings when left to sleep after display off, too, but does not happen if the machine is set to never sleep whilst plugged in and left display open.
 
I may have to try that in short term.. though I /think/ that doing a T2 reset may have actually fixed it.. too early to tell for sure yet.
 
I had the same issue. I tried SMC reset and reinstall of High Sierra on formatted disk without success. I exchanged it for the same model and it's not having that issue. I believe there is no "100% chime", my replacement laptop only makes the sound when plugging in to power.
 
I had the same issue. I tried SMC reset and reinstall of High Sierra on formatted disk without success. I exchanged it for the same model and it's not having that issue. I believe there is no "100% chime", my replacement laptop only makes the sound when plugging in to power.

Interesting, it seems to be behaving now after a reset, hopefully.. sadly a straight exchange would be difficult for me now as I bought it in UK and am in Finland!

edit: though I now just had a complete machine freeze instead.
 
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I'm having same problem, but I didn't think the chime was the 100% charged chime, it's the same chime you hear when you plug an iPhone into the charger. I thought the charge cord was coming loose or something? Not sure how as the computer is stationary, but I don't know...
 
I'm having same problem, but I didn't think the chime was the 100% charged chime, it's the same chime you hear when you plug an iPhone into the charger. I thought the charge cord was coming loose or something? Not sure how as the computer is stationary, but I don't know...

I think I just assumed it was a charged chime incorrectly.. The fact it only occurs whilst asleep, and I think only when at or near 100% charge to me suggests its a management chip issue.
[doublepost=1532248222][/doublepost]Having just done an experiment, it definitely seems to makes a chime when it hits 100%, whether it should or not.
 
I think I just assumed it was a charged chime incorrectly.. The fact it only occurs whilst asleep, and I think only when at or near 100% charge to me suggests its a management chip issue.
[doublepost=1532248222][/doublepost]Having just done an experiment, it definitely seems to makes a chime when it hits 100%, whether it should or not.

And still continues to make occasional chime.. I hope this is something a FW update can fix as getting my laptop exchanged would likely be tricky now..
 
And still continues to make occasional chime.. I hope this is something a FW update can fix as getting my laptop exchanged would likely be tricky now..
Are you able to at least set up appointment at Apple store and see if you can get a new power adapter and UBC C cable to test? it's same model as 2016-2017 adapter.
 
Are you able to at least set up appointment at Apple store and see if you can get a new power adapter and UBC C cable to test? it's same model as 2016-2017 adapter.
I live in a country with no Apple stores, but I can see about visiting the nearest third party aasp maybe next time I'm in town.

At lest the issue doesn't seem to prevent charging or actual use whilst turned on, but it is pretty annoying if can't leave closed on desk asleep without just randomly chiming once charged up.
 
My laptop also constantly wakes itself up when plugged into power, like every two minutes and repeats the same string of wake reasons that I can't figure out. Not sure if its related.
 
Interesting, it seems to be behaving now after a reset, hopefully.. sadly a straight exchange would be difficult for me now as I bought it in UK and am in Finland!

edit: though I now just had a complete machine freeze instead.

I've been having the same issue with a brand new 2019 MacBook Pro. Only when in sleep mode, about every minute, it "dings" and show "100% charged" on the screen for a brief moment. I finally tried resetting the NVRAM/PRAM, logged back in and put the computer to sleep. It happened again but only once, then seemed to have stopped. Finger's crossed that it will behave properly now.
 
I've been having the same issue with a brand new 2019 MacBook Pro. Only when in sleep mode, about every minute, it "dings" and show "100% charged" on the screen for a brief moment. I finally tried resetting the NVRAM/PRAM, logged back in and put the computer to sleep. It happened again but only once, then seemed to have stopped. Finger's crossed that it will behave properly now.

UPDATE: It seems like this only happens with (some) non-Apple power adapters. I never get the "connect chime" issue when the Apple-supplied adapter is being used but have experienced this issue with two other brands. Perhaps these other manufacturers are not complaint on all of Apple's specifications. Seeme like even power adapters are complicated pieces of technology these days.
 
UPDATE: It seems like this only happens with (some) non-Apple power adapters. I never get the "connect chime" issue when the Apple-supplied adapter is being used but have experienced this issue with two other brands. Perhaps these other manufacturers are not complaint on all of Apple's specifications. Seeme like even power adapters are complicated pieces of technology these days.

USB-C has it's own logic circuits that negotiate with the charger to provide appropriate power through a process called Power Delivery(PD). So yes you are correct, it is more complex. This also means people need to be careful when selecting Power Supplies. Quality and rigid adherence to the USB-C PD specification matters. Same for cables. Cheaping out can kill a USB-C port or the entire system.

Even people that should no better, like the engineers Raspberry Pi team, had to learn this lesson. Their new Raspberry Pi 4 cannot work with certain USB-C cables and chargers because of the parts they selected.
 
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