At some point in Novemer last year I updated the computer to Big Sur 11.6 from a previous version of Big Sur, and immediately noticed that I could no longer control the screen brightness via any method - keyboard, Control Center, System Preferences, or Terminal - and that the brightness was stuck at around 50-75%. The keyboard brightness controls don't have any effect, the brightness slider in the Control Center is grayed out, and there is no brightness control at all in System Preferences. Attempting terminal commands to change the brightness also produced no result. The display brightness isn't adjustable in any alternate boot mode either - safe mode, recovery mode, or even when booted into an installer from a USB drive.

Things I've tried:

• Multiple SMC and PRAM resets.
• Reformatted the SSD and performed a clean install downgrade back to an older version of Big Sur from USB.
• Tried that again, this time also deleting the recovery partition if my memory is correct - this was in December.
• Updated back up to Big Sur 11.6.
• Disconnected the battery.
• Unplugged and reseated the display cables to the logic board.
• I even decided to try out an OpenCore Legacy Patcher Monterey installer I had sitting around to see if forcing a newer os install might refresh something, but the same problem persists.

I'm attaching screenshots of what the Control Center and System Preferences show.

Nothing I've tried has had any effect, and the display brightness still cannot be controlled. The computer has sat for months now because I replaced it with a new M1 Pro Macbook Pro in December, and the old laptop became a low priority. It bothers me though to have an otherwise perfectly functional Macbook Pro that was broken by a software update. Is there anything else I can try as a computer-savvy person? (I don't know if the Apple store would even work on this laptop, as it is "vintage" and has had non-Apple repairs made to it in the past.)

As an aside, the computer has an aftermarket SSD, and a replacement display installed by me. The replacement display worked flawlessly for about three years before this issue happened, so I don't think it's the fault of the display.

Thanks.

⟐ Commented March 02, 2026 at 13:47 MST

I’m working on a MacBook Pro 15" Retina Mid 2014 (MacBookPro11,3) that has been freezing and shutting down repeatedly. The crashes happen more often when the laptop is moved, if it's on a desk it works.

After analyzing multiple kernel panic reports (panic: initproc exited, with repeated “Root disk errors: Could not recover SATA HDD after 5 attempts”), ChatGPT told me it strongly points to a failing Flex I/O Board Data Cable (the belt-like ribbon cable, not the rigid plastic I/O cable), as per below image:

I’m trying to replace this cable, but I’m having trouble finding a clear step-by-step guide or video that shows how to remove and reinstall it without removing the logic board. I looked everywhere and I couldn't find it.

From what I understand so far:

• The cable has two different connector styles:
  • One end (I/O board side) is a standard ZIF connector with a metal retaining flap, which I can access and open normally.
  • The other end (logic board side) is partially hidden under the logic board and appears to also have a ZIF-style connector, but the flap is not accessible unless the logic board is removed.
• Based on research and advice I received from ChatGPT, the intended removal method does not require opening the hidden flap:
  • After disconnecting the accessible I/O board end, the cable should be removed by sliding it laterally (parallel to the logic board) from the I/O board side toward the batteries / a nearby screw, by only a few millimeters.
  • Sliding it this way should allow the logic-board end of the cable to disengage from the ZIF socket even with the flap still closed, since the flap prevents vertical lift but not horizontal withdrawal.

• This would explain why ChatGPT told me this operation doesn't require logic board removal for Flex I/O cable replacement, even though logic board removal guide I found on this website mention flipping the retaining flap (step 34).

Before proceeding, I’d like to double check:

1. Is this sliding method correct for removing the Flex I/O Board Data Cable on a Late 2013 / Mid-2014 15" MBP without removing the logic board?
2. Is it expected that the cable feels tight at first and only slides 2–3 mm before coming free?
3. Are there any photos, videos, or firsthand confirmations showing this exact step?

I want to avoid forcing anything or damaging the logic board socket, so any clarification from someone who has done this repair would be greatly appreciated.

Thanks in advance!

⟐ Commented January 21, 2026 at 16:14 MST

ظهور خطوط في الشاش وتتغير بعد اول ٥ دقائق من تشغيله

⟐ Answered January 10, 2026 at 17:33 MST

⟐ Commented January 02, 2026 at 3:41 MST

There is also no Phillips head screwdriver supplied with the kit nor double sided tape to put back the black trackpad cover.

What size phillips head screwdriver is used to unscrew the track pad to reinstall a new one?

⟐ Edited November 26, 2025 at 11:10 MST

I have a macbook pro from mid 2014 A1398 with MacOS Big Sur, and my battery died - it will not charge, but i can turn it on with the magsafe brick. At the same time my screen stopped working (only displays over HDMI), Can the battery cause that issue?

Thanks for help!

⟐ Answer edited November 17, 2025 at 16:05 MST

Anyway to cut a long story short, I went to turn on the machine to check to see if it was ok before packing it up ready for sale when mid way through the boot chime, the MacBook shut down suddenly and now won't re-boot at all.

I've tried the usual, reset SMC, didn't work because the magsafe didn't turn green, tried resetting the PRAM for what it was worth, tried powering up the MacBook without the battery plugged in and nothing. I'm certain that the Logic Board is at fault, but I just want to exhaust every possible option I can before I give up and write it off as a parts machine.

If anyone can give me any ideas as to what I can try, I'd love to know. Thanks.

Additional information: the machine has a 2.2GHz i7-4770HQ, Intel Iris Pro graphics and 16GB RAM with a 256GB SSD.

⟐ Answered September 14, 2025 at 9:31 MST

I just replaced the entire display on my Macbook Pro (Mid 2014) 15” Retina. It was taken from a working machine, according to the seller. I followed the instructions to replace, and it “works” but the bottom of the screen has uneven backlighting. Also, the entire screen doesn’t seem as bright as the original even at full-brightness setting. What could be the cause of this? A bad cable perhaps? I am attempting to return the display I purchased, but wondering if there’s anything else I can do in the meantime to try and get it to work properly.

⟐ Commented August 15, 2025 at 8:00 MST

It doesn't change, it doesn't start. Makes a strange clicking sound like once a second very faintly, sounds like a short to be honest... Tried to reset SMC, no help. Any ideas? Maybe remove all components again and reinstall one more time? Why is it making this sound?

Details:

Connecting charger

When the magsafe is connected, charging light blinks green once, then blinks orange once with long pauses. There seems to be a clicking noise coming from the logic board (coil or mosfet?). The orange light does not blink at the same frequency as the clicking sounds.

Pushing power button

Clicking sound changes and seems to go elsewhere on the logic board with a faster frequency (2 Hz maybe?).

Resetting SMC

Holding all 4 buttons to reset SMC clicking goes away while holding the buttons. After releasing the buttons, charging light flashes green but laptop still doesn't start.

Trying old battery

Same issue

⟐ Commented July 29, 2025 at 8:23 MST

⟐ Answer edited June 21, 2025 at 19:16 MST

Here is the MacOS System Report:

Battery Information:

•   Serial Number: D861015004NDGDL3T
•   Manufacturer: SMP
•   Device Name: bq20z451
•   Pack Lot Code: 0
•   PCB Lot Code: 0
•   Firmware Version: 2
•   Hardware Revision: 00aa
•   Cell Revision: 2
•   Charge Information:
•   Charge Remaining (mAh): 388
•   Fully Charged: No
•   Charging: No
•   Full Charge Capacity (mAh): 5643
•   Health Information:
•   Cycle Count: 27
•   Condition: Service Battery
•   Battery Installed: Yes
•   Amperage (mA): -3719
•   Voltage (mV): 10850
• Here is the CoconutBattery report:

⟐ Commented May 31, 2025 at 8:19 MST

• charge all the way up to 100%
• kept charging for 2+ hours
• using the battery until the laptop shuts off

but after that, after charging it up back to 100% and trying to use it, it's been shutting off randomly for me.

i've tried:

• resetting PRAM
• resetting SMC

and it's still shutting off randomly. both plugged in and not plugged in.

I checked MacOS system information. Under hardware, it says cycle count: 2, condition: normal. so maybe the battery is not faulty?(saw a few ifixit threads where people had to get replacement battery from ifixit, hopefully i won't have to do that)

some of the scenarios i'm running into:

• earlier it would turn off in the middle of watching YT videos
• now it's been like: turning on the laptop, with the battery connector showing green LED which means it's fully charged, but after logging in, the laptop shuts down immediately

I saw another post linking to this article about disabling csrutil but i'm avoiding that for now.

currently for testing i turned on the laptop while holding cmd + r and in the "MacOS Utilities" screen it's been ~30 minutes and the laptop is not shutting down. could there be some application during normal login that would cause the laptop to shut down?(didn't think that was possible)

unfortunately i cannot get coconutBattery because it requires macos12, and i'm running macos10(and i don't want to run installer to update then laptop shuts down randomly during lol

what could be the issue? thanks!

⟐ Commented May 26, 2025 at 20:16 MST

Can I order and replace the battery on my own or should I take it to the Apple Store (which I don't want to as far as possible)?

⟐ Commented April 19, 2025 at 18:32 MST

Battery: NuPower Battery for 15" MacBook Pro Retina Mid 2012 to Early 2013

Laptop: MacBook Pro (Retina, 15-inch, Mid 2014)

⟐ Commented March 21, 2025 at 17:08 MST

Original symptoms were short battery life and touchpad physical clicking not working. I bought a replacement battery and touchpad.

Battery was definitely bulging and putting pressure on the touchpad. I swapped out both and when booted back up - no mouse movement or clicking at all from the touchpad. External mouse works fine, so I went into system preferences and then Touchpad. It said "Touchpad not detected" or something along those lines and had a spinning circle indicating that it was searching for bluetooth touchpads.

So I opened it back up and swapped in the original touchpad - mouse movement but no clicking. But still, system preferences says it doesn't detect a touchpad (I was hoping to at least turn on tap to click.)

So, what am I missing? Is there some extra step to set up the touchpad with the OS? Does the lack of movement on the replacement pad mean that it's DOA?

Thanks for any help!

⟐ Commented March 20, 2025 at 5:35 MST

I tried to reach the trackpad adjustment screw without removing the battery first and peeled some of the tape (see pics) off some battery cells. I also tried to fold the tape "flap" on the two center cells to reach that screw, but still couldn't reach it. Is it okay to reuse the battery pack after some of the tape has been peeled:

also, is it okay that there're some 'creases' on the battery cells, see below:

and also, what kind of adhesive/tape would you use for the metal plate on top of the trackpad:

⟐ Answer edited March 09, 2025 at 3:40 MST

A few weeks ago my MacBook fell from the front passenger seat when I slammed on the breaks and then it started making a crackling noise every once in a while.

It sounded like this https://www.youtube.com/watch?v=rx7Nwp9S...

And now its gone worse, it has a constant buzzing noise through the speaker and even when I plug in my earphones in the headphone jack. And the noise increases and decreases by changing the volume.

However when I plug in a thunderbolt dock, the noise goes away.

https://youtu.be/B-hlTRGn4nc

Now, is this something that is user serviceable? If so, which parts and tools do I need and can I get them from iFixit?

Thanks for any suggestions.

⟐ Commented February 19, 2025 at 2:54 MST

I'm a little afraid to speak ahead of time, but here's an interesting thing I noticed. As a result, during the last week, I no longer had a green tint, and the screen works absolutely fine. A possible solution - I endured this problem for several months, it didn't get any worse or better. And a week ago, in a fit of nostalgia, I wanted to play GTA 4. I installed it via Bootcamp, set the settings to the maximum, not counting the resolution, and played for about 15 hours.

And that's it, after that, the green shade seemed to have disappeared forever. I hope so.

I don't know what the reason is, maybe somewhere something has warmed up, maybe possible moisture has evaporated, etc. But it obviously helped that the mac was under load, the coolers were noisy, the temperature was high.

I hope this will help someone else with a similar problem.

⟐ Answered January 16, 2025 at 17:35 MST

⟐ Edited January 13, 2025 at 10:49 MST

Recently it went into a boot chime loop, and form owning the same model before I disconencted the batetry and booted it fine, but with throttled performance. I ordered a new battery and fitted it only to get the boot chime loop. Got another battery and the same boot chime, so I figired it must be hte machine. With no battery insatlled the machine worked perfectly fine apart from it being slow, so I really didn't think there was an issue.

There was a reference to on old windows partition from either when I owned it or the prevoius owner. I'd a head injury in 2013 so I have memory issues, but I don't remember insatlling a windows bootable partition on it. I use GPT and checked with it for ideas and it suggested resetting the SMC and NVram. I did that and the thing died, no more booting. If I touch the power button the fans spin up weakly. I removed the SSD and tried boooting, weak fans, I disconencted the IO board and SSD and tried booting, weak fans.

If I hold the power button, connect the battery and then the pwer supply, and let go of the power buttons I get a whoosh of the fans. I did this because on an ifixit post somebody suggested this to see if the logic board was still good. Could the board have gone bad from an Nvram clearing? - I've tried every concievable confiruration of button pressing to boot into recovery or safe or evry other mode and all that happens is the bloody fans spin up as soon as I het the power button, if i hold the power button down again for about 10 second the fans turn off. If i disconenct and reconnect the power cord they come on again.

Can anybody help please because GPT broke my machine, well I broke it taking GPT's advice as gold. All help is appreciated because I am buggered if I can't get it working. I have a second machine same model and year and I can't get version of apple's configurator that'll work on that machine. I also connected an external monitor, but it didn't help.

⟐ Commented December 23, 2024 at 7:08 MST