Q: 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
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
Posted on Sep 14, 2016 7:44 PM
