Model A1286. Released February 2011 / 2.0, 2.2, or 2.3 GHz Quad-core Intel Core i7 Processor

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How to unshort or unstick power button?

Hi,

I've been fighting a tough battle with a Macbook Pro 2011 which I am attempting to resurrect after a bulging battery caused it to be cast aside.

I've seen a few related questions but none seem to replicate the strange combination of properties exhibited by this machine.

I'd love to hear what you know about problems of this nature and suggest things for me to try.

I've outlined the problem below and what I have done to diagnose it so far.

Symptom:

The Macbook Pro will automatically shut down when there is no mouse or keyboard activity for a number of seconds (sometimes 5+, sometimes 10+).

This occurs during the boot sequence (apple icon and loading bar, after about 50%) as well as after logging in (the "do you wish to shutdown" popup appears just before turning off).

Other important diagnoses:

1) Pressing the power button does not boot the computer

2) To boot, I instead have to press the key combination SHIFT+CTRL+ALT.

When these three are let go, the status indicator LED appears and the PC boots with a chime.

I believe this is due to triggering the SMC reset sequence. I DO NOT need to press/release the power button in order to get it to boot. I would love to hear if this opinion is correct.

3) With the charger disconnected, after holding the power button down for 10 seconds and reconnecting the charger, the fans will whir at full speed as soon as I release the power button.

This is strange to me, because if the power button itself were damaged, holding or releasing the power button for any duration is not likely to have any effect.

Please tell me what you think of this!

Additional Information

  • The laptop has no battery attached, it is running solely off the adapter.
    • I have attempted to add a battery (which was bulging dangerously) and it had no effect.
    • I believe this is unrelated to the problem at hand.
  • The battery had bulged and bent the aluminium body and cracked the touchpad
    • The touchpad functions perfectly still, I can only imagine the bulging aided a short or possible damaged a component.
  • To avoid unrelated questions about the drive, it is a new SSD on a fresh install of El Capitan with no problems.
  • I can hold down the power button myself whilst still moving the mouse and pressing keys and it shuts down as if the power button was functioning normally.

My problem sounds very similar to the one described here:

power-button-acts-like-it-is-stuck-on-mb...

Fixes I have tried

  • Booting in safe mode: the hard-shutdown still occurs after logging in and stopping key/touchpad activity
  • Clicking the shutdown button on the popup dialog that appears briefly after having logged in and touching nothing (I'm not convinced pressing it does anything as the laptop hard shuts down almost immediately after clicking it).
  • SMC reset: I think that pressing the SMC reset keys is all that is helping this computer boot at the moment.
  • PRAM reset: I cannot see how doing anything memory related will help here anyway.

With the responsiveness of the power button to the fan test and holding it down manually, it seems to me as though some other aspect of the power board is shorting, constantly sending shutdown signals.

I don't know why these signals are interrupted by keyboard / touchpad activity, please let me know why this might be!

I have all the most regular tools and will happily document my findings for any poor souls who have this same problem.

Thanks!

Answered! View the answer I have this problem too

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Wow that's some detailed explanations here. Could you check the keyboard cable for me and tell if the Laptop ever got wet? Thank you.

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The keyboard cable looks under the cable cover look good. I was looking under the metal cover just to the right of the battery connector.

I saw a ribbon on the right-hand side covered by a ribbon which wasn't attached. This looks like the protective flap I've seen in pictures so I assume it was correct this top-most ribbon wasn't connected.

From my tests all key presses worked when the OS was booted.

I don't think the laptop ever got wet, however as I am fixing it on behalf of someone else I can't be sure it didn't happen at some point.

Having fixed other laptops that had water damage, I can't see the tell-tale signs I'm used to.

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There does appear to be some discolouration on the motherboard just above the ribbon:

http://imgur.com/a/bRNGb

Could this indicate shorting or bad connections?

by

@jvanoers that's fine, the discolouration is not from liquid it is from age. Usually these unoccupied points on the board go brown or fade.

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2 Answers

Chosen Solution

Common issue, moving the mouse/pressing keys will interrupt the power button. Basically the power button isn't being held down, but is pressing itself rapidly.

Disconnect the keyboard and battery, then plug in the charger. The MacBook should boot into the OS. If it is not turning itself off, you know the problem is with the power button (attached to the keyboard), so the keyboard will need to be replaced.

Trackpad has cracked since the battery expanded, pushed on the back of the trackpad and cracked it. Replacing this is easy enough.

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Disconnecting the keyboard seemed to allow it to boot and turn on without shutting down. It looks like the problem lies there!

Is replacing the whole keyboard the only way? Is there any way the short can be corrected without needing to replace the entire component?

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You may be able to remove the power button and clean it, but this will not permanently resolve the issue. Best to replace it if you get to this point.

It's easy enough to replace, just has a lot of screws to remove and replace, but not much to go wrong. If you don't have the tools, it would probably be best to send it somewhere, since they are usually offered as cheap repairs.

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Thank you for the image !

Before replacement always clean all the connectors and dirt from the board.

I use cleaning benzine with Q-tips to fry the stuff away.

If that didn't help you should get a used keyboard of from eBay or else.

Good Luck.

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Jaime will be eternally grateful.
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