Powerbook restarts when magsafe removed

Question

Powerbook restarts when magsafe removed

When I disconnect power, either by removing the wall plug or by pulling the magsafe away from the laptop, the laptop immediately restarts.

When the laptop is kept connected it operates and charges normally. If it is running on battery it operates normally.

Macbook Pro, 2012, 13"

I have tried resetting the manager, and bought a brand new power adapter. No change.

My next idea is to erase the whole system and reinstall the OS from scratch and see if that might have a glitch but I really would like to avoid that.

I see a lot of threads where the powerbook has power issues and shuts down, or won't charge, etc. None of those seem to describe my issue.

Anyone?

MacBook Pro

Posted on Apr 28, 2021 6:16 AM

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Answer 1

Best reply

Allan Jones

Level 9

68,834 points

Apr 28, 2021 7:31 AM in response to culturalproduct

Welcome,

Try an SMC reset:

How to reset the SMC of your Mac - Apple Support

Your MBP does not have the T2 security chip, so you can skip that part. The SMC has a lot to do with power management.

Let's look at the battery condition anyway. What does System Information say about battery condition. You can open SI from Applications > Utilities, or from "About this Mac..." by clicking the "System Report" button.

Cycle count is most important. The SI report shows that:

The part in red show the most useful data. Please post the values shown inside the box I outlined. That will not give away any personal information.

I see a lot of threads where the powerbook has power issues and shuts down,

FYI: A MacBook Pro is not a PowerBook, The MBP replaced the Powerbook in 2006. Two very different computers. If you are looking up reports under PowerBook, you will find different issues than MBPs usually encounter.

Is this the original battery?

Have you checked the pins on the MacSafe connector in the power port on the MBP? Make sure tehis is no dust/lint in there that could cause intermittent contact and shorting.

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Answer 2

Apr 28, 2021 6:48 PM in response to Allan Jones

Hi, thanks for the reply.

Regrets re mixing up Powerbooks and Macbook Pros, I realize there's a difference just slipped up :)

I have already tried reseting SMC, no change in the issue.

The battery is operating normally, it charges and discharges fine, though lately lasts perhaps 4-5 hours instead of the original 6 hours but that's just age I assume. Anyway the laptop is entirely normal except for the described issue: removing the magsafe connector, or, removing the power adapter from a wall plug, while the laptop is running on AC causes an instant restart.

Attaching the power cord while the laptop is already running on battery is also fine, the laptop just switches to AC from battery normally.

I just bought a brand new power cord in case the problem was with my old original cord. No change.

The magsafe port on the laptop has been cleaned though I found nothing foreign in it.

It is the original battery.

It is getting old but still runs the laptop for 4-5 hours typical use (for me). Or 3 Netflix movies.

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Answer 3

Apr 28, 2021 6:44 AM in response to culturalproduct

Should also mention, when the powerbook is running on battery, I can connect the power adapter while it is running and it has no problem. It restarts ONLY when the powerbook is running while using the power adapter and the power adapter is then disconnected.

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Answer 4

May 12, 2021 2:35 PM in response to culturalproduct

Update:

Have reset PRAM, NVRAM, SMC.

Have erased HD and re-installed OSX Catalina from scratch.

Erased again and rolled back to OSX 10.4 Mojave.

No change.

To recap: MBP runs without any problems.

But - when the magsafe power connector, or, the plug at the wall outlet, are disconnected while the MBP is running on AC, it immediately restarts.

If it is running on battery, the power cord can be connected without trouble.

If the MBP is asleep the power cord can be connected or disconnected without trouble.

If it is shut down after running on AC, the power cord can be disconnected without trouble.

I'd think it was a physical issue except that it can be disconnected while asleep without any problem, which suggests a software issue to me.

Throwing this question back out there...

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Answer 5

HWTech

Level 9

55,880 points

May 12, 2021 6:30 PM in response to culturalproduct

Is this the non-Retina model?

You may have a bad DC-In Board. It has been a while since I've seen this issue, but I think the DC-In Board may have been the solution when it occurred.

You definitely have some sort of hardware issue and the only way to figure it out is by swapping components. Usually it is easiest to try another charger and battery. Do you have access to another charger or battery? If you have the non-Retina model I believe the same battery is/can be used/tested on 2009-2012 models. Temporarily testing the battery between two laptops is a good way to see if the battery or laptop is the problem.

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Answer 6

May 1, 2021 6:51 PM in response to culturalproduct

Now updated Mac OSX to 10.15.7

No change. Still instantly restarts when power disconnected.

Otherwise normal operation.

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Answer 7

May 12, 2021 6:37 PM in response to HWTech

Yes non-Retina version.

I forgot to mention that I did buy a new charger cable, no change :(

I'll try swapping batteries.

Thanks

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Powerbook restarts when magsafe removed

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