MacBook Pro has started randomly shutting down when on battery since upgrading to El Capitan

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Level 1

128 points

MacBook Pro has started randomly shutting down when on battery since upgrading to El Capitan

I have a MacBook Pro (15-inch, Early 2011) that has been working fine on Mountain Lion for a very long time. I finally got round to upgrading to El Capitan last week: straight to 10.11.6. A couple of days later it just switched off without warning while I was working. It was then fine for a few days, but then did it several times in the last 48 hours.

I am moderately sure it only happens when on battery (it hasn't happened in the last 8 hours while plugged in). Every time it happens there is no warning and the Mac then reboots fine (manually) – although the clock always resets to 1970 until it can contact an NTP server. One curious side effect is that my PostScript fonts were blank onscreen in Excel for a few reboots yesterday, but then were OK again!

No hardware has changed. Only major software change is El Capitan, and possibly an update to iStat Menus.

I have reset PRAM and SMC. I have run the short AHT. I have taken the machine apart and cleaned the fans; they were OK, but the issue does seem to happen when the Mac is hot.

Spotlight and Time Machine have at times seemed to be struggling since the upgrade, and I also saw rpcsvchost using 100% of a core for a while. Sometimes the machine feels sluggish – but for the last 8 hours it's been fine. The only pattern I have established is that it seems to only happen on battery; it even happened while the Dock (etc) were loading after logging in following an unexpected shutdown.

The other common thing is this in the logs every time:

Previous shutdown cause: -128

I have scanned a number of posts related to aspects of this, but not seen one that lays the blame on El Capitan rather than hardware. Yet, many people are reporting this sort of issue after upgrading… Coincidence?

Any ideas?

Thanks.

MacBook Pro (15-inch Early 2011), OS X El Capitan (10.11.6)

Posted on Sep 14, 2016 6:08 PM

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Answer 1

John Galt

Level 10

156,998 points

Oct 18, 2016 3:15 AM in response to Rich Walsh

Previous shutdown cause: -128

A negative shutdown code usually indicates a hardware fault. Have Apple evaluate your Mac. The fix might be as simple as a replacement battery.

Start here: Contact Support

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Answer 2

Rich Walsh Author

Level 1

128 points

Sep 17, 2016 1:47 PM in response to John Galt

I was fairly convinced it wasn't a hardware fault (-128 is "unknown"), as it only started once I upgraded the OS. However, after gathering more evidence that it only ever happened on battery and always reset the system clock I figured it must be something battery-related, so thought I'd at least check by booting from an old Mountain Lion backup. In fact, I didn't even need to do that as I went into Recovery to turn the Open Firmware Password off to make this all a bit easier and realised I could just leave it sat booted from there on battery to see if it switched off – which it duly did. So it is hardware as if it can't stay alive on the Recovery partition then something's up…

I took it apart to see if I could find any cracks, etc, around the battery connector. I found that this clip was split in two (picture borrowed from iFixit):

It's labelled "818-0676" and seems to be intended to enclose a lug on the bottom case. I put a tape splint on it and taped over the lug to prevent any shorts, hoping that would fix the issue until I could get a replacement part. Sadly not – it happened again. Although the battery appears healthy could it be disconnecting when under load? Or is it more likely a logic board failure?

I will progress through Apple and a local service provider. I have noticed the following:

It only happens on battery, and can happen when the Mac is sitting completely still and unattended
Intervals between occurrences probably get shorter as the machine gets hotter – so something is expanding
The system clock is always reset to 1970, and nothing is recorded in the logs: it's as if power has been switched off without warning
Once it has happened, pressing the power button will cause the front LED to pulse once and the DVD drive to make that familiar whirring sound; it doesn't start the Mac and the LED goes off
It takes a second press on the power button to actually start the machine, and the DVD drive whirs twice before the screen comes on (it's only ever once when starting normally)
The battery LEDs on the side still show the battery as working at all stages of this process

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Answer 3

Rich Walsh Author

Level 1

128 points

Oct 18, 2016 3:20 AM in response to John Galt

My local (and brilliant) service provider Apple Bay diagnosed a failed battery and charger port – having initially suspected a blown capacitor on the logic board. It may be coincidence that it started when I upgraded to El Capitan, or the higher demands of this OS may have tipped it over the edge – there was certainly a few hours while the machine ran very hot while installing the upgrade.

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