MacBook Pro 2012, (2.5Ghz, i5), Mac OS 10.12
Was working fine, regularly booted up and ran fine.
Was completely shut down (not sleeping), left connected to a charger which was plugged into a surge protector. Some time while we were out there was a power outage.
The next day (after the power came back on) when attempting to turn on the Mac there was no response whatsoever. The Magsafe adapter’s LED glow was an extremely dim green. I connected it to a different MagSafe which had not been connected or in use which revealed the same dim green glow.
Research indicated that resetting the SMC might be the solution. I followed the steps described on “Reset the System Management Controller (SMC) on your Mac”
Reset the SMC on Mac notebook computers …where battery is non-removable:
Pressing the power button, Magsafe adapter’s LED returned to normal and the Mac DID turn on. I didn’t immediately log in. After 20, 30 seconds or so it shut down and again wouldn’t power up. I tried the SMC reset process again several more times to no avail. The LED became dim again. It would not boot.
Another possible solution I found suggested:
After starting up, I used it for an hour or so and it behaved normally. It was shut down and successfully restarted several times.
Battery Health, for what it's worth, is at 86%
battery Age: 5 years
Cycles: 709
It seemed to have returned to normal until, a little over a day later, I found that it again wouldn't boot up and I, again, had the dim glow from the adapter. Resetting the System Management Controller again got it up and running & I’ve now been using it with no problems for somewhere around 10 hours.
I have not tried anything else such as resetting permissions, zapping the PRAM, etc. as this seems to me it should be more of an SMC reset issue…but I wouldn't think it should have to be reset repeatedly. Any suggestions as to what may be the cause of this, other applicable resets, possible solutions, etc. would be very much appreciated.
It may be a coincidence but I’ve been attributing this to the power coming back on. Several years ago, I “coincidentally’ lost two iMac power supplies after similar circumstances. Could this be the case? I've read that laptops don't succumb to this as often due to the battery offering some sort of a buffer. But if this was responsible is there physical damage to hardware, the battery or only causing software issues? If it is software issue, is there another reset that could be done or something that could be “cleared” to return it back to normal?
As I don't know what will happen, whether it'll reboot again after I shut it down next time I'll go ahead and ask these now, as well …/just in case.
I remember that the G4 iBooks required a functional battery to operate even when powered by the power supply. We have an earlier (2008) MacBook here that will happily run powered by the Magsafe adapter with no battery installed whatsoever.
What is supposed to be the case with the MacBook Pro 2012?
Should it power on when connected to the power supply with a bad battery installed?
Should it power on when connected to the power supply with the internal battery disconnected?
Thanks very much for any helpful information, additional troubleshooting tips, suggestions or, ideally, solutions.
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Was working fine, regularly booted up and ran fine.
Was completely shut down (not sleeping), left connected to a charger which was plugged into a surge protector. Some time while we were out there was a power outage.
The next day (after the power came back on) when attempting to turn on the Mac there was no response whatsoever. The Magsafe adapter’s LED glow was an extremely dim green. I connected it to a different MagSafe which had not been connected or in use which revealed the same dim green glow.
Research indicated that resetting the SMC might be the solution. I followed the steps described on “Reset the System Management Controller (SMC) on your Mac”
Reset the SMC on Mac notebook computers …where battery is non-removable:
- Shut down your Mac.
- Unplug the MagSafe or USB-C power adapter from your computer.
- Using the built-in keyboard, press Shift-Control-Option on the left side of the keyboard, then press the power button at the same time. Hold these keys and the power button for 10 seconds.
- Release all keys.
- Reconnect the power adapter.
- Press the power button again to turn on your Mac.
Pressing the power button, Magsafe adapter’s LED returned to normal and the Mac DID turn on. I didn’t immediately log in. After 20, 30 seconds or so it shut down and again wouldn’t power up. I tried the SMC reset process again several more times to no avail. The LED became dim again. It would not boot.
Another possible solution I found suggested:
- Unplug the power adapter from your Mac
- Remove rear screws, Remove back panel
- Disconnect the battery
- Plug in power adapter & attempt to power up,
- Shut down, disconnect power
- Reconnect battery, reconnect power adapter, Restart Mac
After starting up, I used it for an hour or so and it behaved normally. It was shut down and successfully restarted several times.
Battery Health, for what it's worth, is at 86%
battery Age: 5 years
Cycles: 709
It seemed to have returned to normal until, a little over a day later, I found that it again wouldn't boot up and I, again, had the dim glow from the adapter. Resetting the System Management Controller again got it up and running & I’ve now been using it with no problems for somewhere around 10 hours.
I have not tried anything else such as resetting permissions, zapping the PRAM, etc. as this seems to me it should be more of an SMC reset issue…but I wouldn't think it should have to be reset repeatedly. Any suggestions as to what may be the cause of this, other applicable resets, possible solutions, etc. would be very much appreciated.
It may be a coincidence but I’ve been attributing this to the power coming back on. Several years ago, I “coincidentally’ lost two iMac power supplies after similar circumstances. Could this be the case? I've read that laptops don't succumb to this as often due to the battery offering some sort of a buffer. But if this was responsible is there physical damage to hardware, the battery or only causing software issues? If it is software issue, is there another reset that could be done or something that could be “cleared” to return it back to normal?
As I don't know what will happen, whether it'll reboot again after I shut it down next time I'll go ahead and ask these now, as well …/just in case.
I remember that the G4 iBooks required a functional battery to operate even when powered by the power supply. We have an earlier (2008) MacBook here that will happily run powered by the Magsafe adapter with no battery installed whatsoever.
What is supposed to be the case with the MacBook Pro 2012?
Should it power on when connected to the power supply with a bad battery installed?
Should it power on when connected to the power supply with the internal battery disconnected?
Thanks very much for any helpful information, additional troubleshooting tips, suggestions or, ideally, solutions.