⟐ Commented 九月 24, 2025 at 1:15 GMT-7

按下开机键后，屏幕没有反应，黑屏。键盘灯不亮，背面的苹果LOGO灯不亮。

只有风扇声。

⟐ Answered 十二月 03, 2024 at 1:40 GMT-7

去授权店进行检修说是屏幕出问题了，后面又去直营店天才吧进行检修，说是可能和系统有关。但是我已经进行过抹盘重装，系统无论是升级到10.4还是10.15都会出现这个问题。

另外我装了双系统，在windows下面没有出现过此种情况。

黑屏状态如图（背光正常）

I got a 2017 13” MacBook Pro online for parts. The fans gradually ramp up and spin at full speed when plugged in. The trackpad connector was ripped off of the board and there is no ssd. Water damage indicators are also red, but no visual marks or stains. I get no image on the display, caps lock key does not light up when I press it. When unplugged, the system immediately shuts down. Any help?

⟐ Commented 七月 26, 2026 at 19:25 GMT-7

Essentially, my Macbook Pro M1 16GB 2020 (A2338) camera has stopped working. Not sure why. If I open Photo Booth, the screen is black but there is no message/warning. The camera light does NOT switch on either.

Tried the following:

• Restarting
• sudo killall VDCAssistant and AppleCameraAssitant but it says No matching processes.
• Reset the laptop (factory reset using iTunes)
• Took off the bottom cover to confirm the 4 ribbon cables were still connected from the screen

If I go to my system information, then go to my camera, it says "No video capture devices were found".

Everything else works perfectly fine so not sure why it would be the camera hardware itself.

⟐ Commented 七月 26, 2026 at 10:38 GMT-7

My display backlight was working perfectly just a day ago, but ever since I connected the display into another MacBook I was testing the backlight completely stopped functioning. I already swapped the small cable that connects the display board with the logic board and have also tried SMC/PRAM reset without luck. Connecting another display to the MacBook shows nothing either (this screen was untested however). Any help?

⟐ Answer accepted 七月 25, 2026 at 12:01 GMT-7

⟐ Commented 七月 24, 2026 at 6:01 GMT-7

Troubleshooting steps - I've basically done everything software wise, so I know it's hardware. Chat GPT seems to believe it's the backlight fuse that may have blown due to liquid entering.

Anyone have a hunch on what's happening? I know liquid is difficult, as I've actually worked at an Apple Store as a technician. This was a used purchase and I'd rather not spend a whole lot fixing it, but I'd like the backlight to work.

I do not have soldering equipment or a microscope, but I'm comfortable disassembling and stuff at home (I've replaced thousands of phone batteries and displays, and I build computers as a hobby). Thanks!

⟐ Commented 七月 24, 2026 at 4:04 GMT-7

I’m looking for a board-level diagnosis for my MacBook Pro Retina 15” Mid 2015 (A1398).

Configuration

• Intel Core i7
• 16 GB RAM
• macOS Monterey 12.7.6

History

Before repair:

• The original internal display was cracked but still displayed an image.
• The Mac worked perfectly with an external HDMI monitor.

During repair:

• A technician installed a display from a MacBook Pro 2013.
• The replacement display never worked.
• He reinstalled my original cracked display.
• Since then, the internal display has been completely black.

Current behavior

If the internal display cable is disconnected:

• Apple logo appears on the external HDMI monitor.
• Startup Manager (Option key) works.
• Internet Recovery works.
• But when booting from Macintosh HD, Recovery, EFI Boot or a bootable USB, the Apple logo appears, then the screen goes completely black.

If the internal display cable is connected:

• The internal display remains completely black.

The Mac appears to continue running:

• keyboard backlight works,
• volume keys work,
• fans operate normally,
• but there is no video output.

Already tried

• NVRAM reset
• SMC reset
• Safe Mode
• Internet Recovery
• Bootable USB installer
• OpenCore Legacy Patcher

Always the same result:
Apple logo → black screen.

Verbose mode also showed messages including:

• device is not readable
• failed to initialize volume keybag

Questions

1. Could installing a 2013 Retina display on a 2015 A1398 have damaged the LCD connector or another logic board component?
2. Which is the most likely cause?
   • LCD connector
   • LCD power/backlight circuit
   • Display cable
   • GPU
   • SSD/APFS
   • Logic board
3. What measurements or board-level tests would you perform before replacing parts?

Any advice would be greatly appreciated. Thank you.

⟐ Commented 七月 23, 2026 at 13:03 GMT-7

Also, is this cable bad?

Edit to add area after cleaning with IPA:

⟐ Commented 七月 22, 2026 at 19:50 GMT-7

Here see the horizontal lines in the Finder icon.

⟐ Commented 七月 22, 2026 at 11:41 GMT-7

⟐ Answered 七月 21, 2026 at 18:32 GMT-7

It turns on, fan spins, but that is it nothing else happens.The sleep light is on.

I have tried, removing RAM, Swapping RAM, Without the KB connected, Without a display, different HDD / SSD, Different working HDD cable, Reset SMC, PRAM etc..... Board looks clean, no water damage evident. Owner siad it just wouldn't start anymore. It does charge the battery though.

⟐ Commented 七月 21, 2026 at 15:42 GMT-7

Observations:
macOS (all versions) detects and recognises the monitors, as in the screen flickers and recognises the brand and supported modes (within adapter limits)
Same goes to the pre-boot environment
Windows does not see the external display even after manual detection. Sometimes after reboot the integrated graphics in Windows is disabled due to a problem, re-enabling it brings back proper graphics but external monitor output is still not working or being detected.
All the adapters I've bought show the MacBook Air, not the MacBook Pro, although I've seen a review of someone using it on a 2012 Unibody MacBook Pro
A while back I had a different MacBook Pro model, still 2011 but the Early 2011 one, with the Core i5 instead of the Core i7. I was given a mini DisplayPort to VGA adapter and same symptoms, macOS and preboot environment sees it, but no display out. I was told by the person that gave the adapter to me that they use it on their 2015 MacBook Air just fine with no problems.

Is there like a common fault or difference with these Unibody MacBook Pros with how they handle that specific port and why it seems to be temperamental with cheap adapters? I haven't tried the adapters I've had since other than specific Lenovo ThinkPad laptops and MacBook Airs, I haven't had the opportunity to try them.

I want to try one of the more expensive adapters but I don't want to spend money on something that is not guaranteed to work.

Let me know if there's anything I could do.

⟐ Commented 七月 21, 2026 at 5:08 GMT-7

⟐ Answer edited 七月 19, 2026 at 15:47 GMT-7

⟐ Commented 七月 19, 2026 at 12:47 GMT-7