기기를 수리하세요 커뮤니티 상점

듀얼 마이크와 802.11ac Wi-Fi 연결 기능을 갖춘 Apple MacBook Air 중 더 작은 노트북.

149 질문 전체 보기

옵션

Unable to reset SMC after battery replacement

I've recently replaced a dead original battery in my ten year old MBA. Most things seems to be going well however these days when the computer gets to the low battery level (~6-7%), the system shuts down rather than just saving current state to disk like it used to, similar to what is described here and here. Now yes, I have read that ideally I should be regularly running the battery and normally I don't but I actually discovered this whilst trying to calibrate the battery and have been noticing it still occurs.

As per this page I have checked for hybernatemode in terminal, it is set to 3 so nothing has changed there. From what I can see, it appears that the only solution for this involves resetting the SMC and hoping for the best.

Unfortunately, I no longer seem to be able to do this since the battery change. I shut down the Mac, hold SHIFT + CTRL + OPT, but pressing the power button does nothing, no chime and/or reboot even after a very long hold. Releasing the combination also does not result in a start up. If I start the machine first and then depressthe 4 buttons, I witness immediate power off with no further action, even after continuing to hold for several minutes. From testing key combinations, it seems to be the power button which is causing this. It has instant effect, rather than the usual delay of up to several seconds that I am used to from performing this process previously.

I am considering disassembling the machine to perform a "hard" reset of the SMC, however I am wondering if a) is this intended behaviour from a new battery? b) is a "hard reset" a good work around? or c) is there something else I should be trying instead?

EDIT: I just tested and the 4 key combo has the instant-kill effect even from the fully-powered state, not something I would have expected.

EDIT 2: here's the screenshot from coconutBattery:

Block Image

EDIT 3: here's another screenshot from coconutBattery, this time in green:

Block Image

Cheers

이 질문에 답하기 저도 같은 문제를 겪고 있습니다

좋은 질문 입니까?

예 아니요
점수 0
댓글 달기

답변 1개

필터:
가장 유용함 가장 최근 가장 오래된

옵션

The four finger salute is often not done correctly. You need to hold the power button a bit to finish the task.

I would just pop off the bottom cover carefully disconnect the battery and then press and hold the power button for a good 15secs. This should clear SMC.

But is SMC the issue here? Let’s get a better view of things install this gem of an App CoconutBattery Take a snapshot and post it here for us to see.

해당 답변은 도움이 되었습니까?

예 아니요
점수 0

댓글 4개:

To clarify, by "very long hold" I mean literally minutes. I've successfully reset both the PRAM/NVRAM and the SMC before on several models, including this machine, which is now behaving differently. I've tried the hard reset and it made the little restart whirr this time, so we'll see if it's had the desired effect.

As for the CoconutBattery readout, you can find the screenshot attached above - does it tell you anything interesting?

의

@laz77651 - Well… I wouldn’t say more than half a minute if you use a watch to time it.

Sadly, the batteries age I think has sunk you ☹️ Let it charge turned off for a good ten hours, then take not of the first bar it should be green now and the system should run. If not then it’s time for a fresh battery.

Sometimes we get so fixated on the cycle count we forget about the age of the battery. Here the cycle count is quite low as you rarely disconnect the system from its charger (13). Yet the battery was manufactured in 2015. So is this in error or is this an old battery? I’m suspecting it was awhile ago that you swapped out the battery. If I’m mistaken you’ll need to contact the iFixit store for a replacement.

의

@danj Sorry my problem was only that I was unable to keyboard reset the SMC. I purchased and replaced this battery a week ago (my "recently"). The lifecycle seems acceptable, I'm a heavy user (maybe 6 hours, though I haven't measured it with a clock, which is in any case a huge improvement on the 1.5 I was getting towards the end of the old battery's life). I've posted a screenshot of the current charge state, which is now green (I deliberately stopped charging around 85%, see reasoning below).

First time I followed the calibration sheet:

• 1) charge to 100%, keep charging >2hrs

• 2) Use device until shut-off due to low battery

• 3) Charge uninterrupted to 100% again

The next charges have been mostly 10-100% charges, with the occasional drain until switch off (at about 6%, as described). From reading around I will be trying to aim for mostly 20%-85% charge cycles to prolong battery life.

Since it's a 2013 11 inch Air, I'm not sure if they even still manufacture batteries for them or just have old stock.

의

@laz77651 - You know there is a point you can go to far!

Two cycles is all that’s needed to set the SMC high and love values for the given battery. Overtime the system will adjust a bit more on its own.

I’m more worried about the batteries age value. You really need to do a hard SMC reset.

Just disconnect the battery, then with nothing plugged in press and hold the power button for a good 15secs to fully discharge the logic board. Now plug in the MagSafe charger, the system should spontaneously restart, let it fully boot up and do a proper shutdown. Now plug-in the battery and restart it again. Give it a few minutes and check CoconutBattery see if the date updates to a more current date. If not contact iFixit to get a replacement battery.

의

댓글 달기

귀하의 답변을 추가하세요

Laz 님은 대단히 고마워 할 것입니다.
조회 통계:

24 시간 전: 0

7일 전: 2

30일 전: 13

전체 시간: 122