Macbook Pro - Mid 2012 (A1278)

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resiteppa Author

Level 1

8 points

Macbook Pro - Mid 2012 (A1278)

Hi guys,

Basically I tried to change the speakers (due to crackling noises) of my MBP and I have some major issues now.

The timeline as follows:

1) I swapped out both L and R speakers today

2) Booted up and all was good; battery was 60% odd

3) After shutting down, I tried booting up again but this time round the LCD screen flickered 2-3 times, boots to mainframe

4) Turned off to try again and this time round won’t start

5) Did a SMC reset and MB booted up again

6) Shutdown again after it won’t boot anymore

7) Magsafe is always in green despite 60%+ and SMC works (changes to amber) but won’t boot and no chime

Latest Update: MBP will not boot without power source. Even with power source, it’s a 50/50.

Can anyone shed some light on this? I’ve tested on other machines for ram and SSD, both work perfectly fine.

Thanks in advance.

MacBook Pro

Posted on Jan 29, 2021 8:21 AM

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Answer 1

Top-ranking reply

Allan Jones

Level 9

79,148 points

Jan 29, 2021 8:33 AM in response to resiteppa

If it worked normally before the service, I would look for loose connectors, especially the battery connector. I assume you disconnected the battery before doign the speakers/? That is Step 1 for any internal service on that model.

One weak spot in the otherwise bulletproof Mid 2012 13-inchers is the hard drive cable. The cable is basically a flexible printed circuit board with painfully thin insulation After 3-6 years of the vibration from normal use and transport, the cable can chafe on sharp metal edges in the chassis, losing some insulation. Possibly the internal work you did moved the cable just enough to let a bare spot on the cable to make contact with metal.

Cables are cheap (US$15), available (here), and easy to install.

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Answer 2

Allan Jones

Level 9

79,148 points

Jan 29, 2021 9:14 AM in response to resiteppa

I did remove the battery connector before dislodging anything else.

Top man! You would not believe how many people skip that step.

Is there any method to check for the cable issue you mentioned?

Not that I know of. Most of us who own or have done upgrades onthat model recommend changing the cable when you change out the hard drive. It is much like service recommendations for automobile engines with overhead cams: install a new water pump whenever you install a new timing belt. Except the HDD cable is a lot cheaper!

Im just worried I short-circuited something which can spell expensive.

Normally the drive cable shorting simple makes the computer act like its drive is acting up or dying.

One connector that is hard to evaluate is the power connector for the cooing fan. It is quite delicate. You might take a look at that with a good lens to see if it looks lifted away from the LB.

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Answer 3

rs09

Level 2

335 points

Jan 29, 2021 8:32 AM in response to resiteppa

Well if the MagSafe stays green it is probably a dead battery. Try pressing the battery indicator button on the side. Do the lights flash 5 times? Not sure about the speakers tho, maybe you missed a few connectors or something. Try opening the machine up again with a tutorial and see if you've messed anything up. Try to resolve the problem if you can.

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Answer 4

resiteppa Author

Level 1

8 points

Jan 29, 2021 8:38 AM in response to rs09

Hi,

It doesn’t flash 5 times. Just shows how much it’s charged to. For now, approx 60% or so, so 4 out of 6 lights.

Ive tried 3-4 times even by placing the old speakers back thinking it could be a crappy speaker issue to no avail unfortunately.

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Answer 5

resiteppa Author

Level 1

8 points

Jan 29, 2021 8:40 AM in response to Allan Jones

I did remove the battery connector before dislodging anything else.

Is there any method to check for the cable issue you mentioned?

Im just worried I short-circuited something which can spell expensive.

For now it’s frustrating that I’ve checked and rechecked and followed the tutorial videos online step by step. Didn’t miss anything and even tried reverting back to the old speakers but to no avail.

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Answer 6

resiteppa Author

Level 1

8 points

Jan 29, 2021 9:17 AM in response to Allan Jones

I see. So this drive cable might be the cause for the problems i’m facing?

ie, can’t boot up, and even chances of booting up keyboard goes haywire?

for some reason when i manage to boot up now, Shift is power button. 🤦🏻 I was trying to do a SMC reset and it got turned on.

this is so frustrating sigh

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Answer 7

Allan Jones

Level 9

79,148 points

Jan 29, 2021 9:44 AM in response to resiteppa

resiteppa wrote:

this is so frustrating sigh

Indeed. Frustrating here too. I love this model (we have two upgraded with more RAM and SSDs) and I'm dying to get my hands on yours to see why it is acting out.

Did you upgrade to an SSD? Not sure from your original post. If so, what model and brand?

I have an appointment in a few minutes and probably will not be able to check back for 3 hours ±

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Answer 8

resiteppa Author

Level 1

8 points

Jan 29, 2021 4:34 PM in response to Allan Jones

Hey Allan,

Sorry for the late reply. I’m on GMT+8

Yes upon purchase my first move was 16GB + SSD upgrade.

Was the simplest one to make this little monster fast.

Cant even run Apple Diagnostics unfortunately. Quite at my wits now.

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Macbook Pro - Mid 2012 (A1278)

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