How do I fix black screen with white line issue on my MacBook Pro screen?

"How do I fix black screen with white line issue on my MacBook Pro screen?: Suddenly this afternoon my MacBook Pro 16 inch (the last of the Intel models) is suddenly refusing to boot up. [...]Worst thing is I’ve just gone on holiday to Italy (from London) and I have work to do but obviously can’t at the moment "

-------

Troubleshooting Mac Boot:

Try the Following:

• Go Here: If your Mac Starts Up to a Blank Screen - Apple Support

• Boot in Safe Mode: [Hold Down: shift key, upon boot], In Safe Mode, Login Items do not run at login, certain preferences are set aside, and damaged system files are then reset. So, once booted in to Safe Mode, wait 30 seconds, and then boot up normally, attempting another update install.

• Bug Fixes: Connect an external screen. See if you can boot up and see it all. If so, try updating your Mac. Updates contain bug fixes. Hold down: [command + F1] or [command + dim screen]

• Reset the SMC and your NVRAM: Sometimes when changes are made to the system(i.e. updates), system configurations (i.e. for Screen) become manipulated, technically. So, reset the SMC and NVRAM

• Use an External Monitor (and maybe keyboard and mouse): What happens when you plug in an external monitor? Is the screen black? Take a screenshot, and see if it is seen as it should. With two screens, you should see two screenshots on your Desktop. Hold down the following: [command + shift + 3]. Then, mirror the screen by holding down [command + F1].

"Thanks for this. Nothing is working. The hard drive isn’t even spinning. I’m thinking it’s dead"

--------

.

Removing Data from a Device Without Power:

I'd agree from all that you've reported and tried. So, try extracting the data..

Is this Covered by Apple Care?

Login here, to find out: Check Your Service and Support Coverage - Apple Support

A. If so...

Take this in for a Genius Bar Appointment at your local Apple Store. Bring a proof of purchase with you. There, it would be diagnosed, and you'd be provided with a cost.

B. If Not:

Take this to an AASP  (Apple Authorized Service Provider). See if they can remove the read drive, and perform the transfer. It would be inserted into a drive toaster, and then they'd perform the transfers. See an AASP (Apple Authorized Service Provider) in your local area...

Contacting an AASP: 

1. Go Here: Find Locations - Apple Authorized Reseller
2. Click: Service & Support
3. Enter: your location information
4. See: if there is an AASP nearby
5. Contact: an AASP that shows up, and find out more about the services that they offer to extract the data

Sounds like a dead laptop, but there are a couple of things that can be tried such as a DFU Firmware Restore, but that requires access to another Mac running macOS 15.x Sequoia at this time.

FYI, I do not recommend repairing any Intel Macs from 2016-2020 for multiple reasons, but especially not the MBPro 16" (2019) model since it's Logic Board has an extremely high rate of failure compared to other models. This forum has multiple posts from users who have mentioned even an officially repaired & replaced Logic Board has had issues needing replacement.....sometimes as soon as they get the laptop home after the repair. The money spent on repairs is much better put towards a new laptop.