iPhone 8 Series & iPhone X, you have to read the old serial number from the old screen and transfer it to the new one with a special programmer (about $500 for programmer on ) to fix the issue with true tone, I never tested on iPhone 11 series but is think it will be the same thing, at soon I have news I will post it here.
Phone has to be checked for a real Professional that has the equipment to test any Chip on you Motherboard, any good place with real Professional will charge you from $100 and up if they have to do a micro-soldering job. Quick Facts: Crazy Percentage on Battery and randomly lost of Power means a Bad Battery. Charging IC is far away from back light Drivers, can be, but can be liquid Damage Too.
Well in common language you need to Replace the Screen it’s all, But The Digitizer/Touch, OLED and Front Glass comes everything together on a slim sandwich. Useless Info: You can remove single layers from the screen if you have a company with $100,000.00 on Screen Repair machines, because is possible to do that, in your case your OLED is damaged (is the more expensive part), so is trash.
Those phones have a Signature Failure, if you understand some basic electronic you can watch this YouTube Video. https://www.youtube.com/watch?v=2T9BVR-oUDM Make sure that your Phone has IMEI Number on Settings and on Phone App Dialing *#06#, make sure that your phone has moden firmware version, and make sure that your phone is reading the simcard on General --> About -> ICCID No services with Warning Sign Changed it to new housing and now NO SERVICE Can be a Disconnected Antenna or a Micro-Soldering Job.
Every case is different, technician needs to check the device and clean, fix or replace damaged components. The best tip is take a desicion quickly you don't want to discharge the battery inside of your phone with liquid , an easily cleaning can be turned on expensive microsoldering repair.
You can't Device is mounted and in use, disk utility is too limited for this easy task. You can clone it with a external bootable macOS. Easy and free way on your existing macOs is Carbon Copy Cloner (Google It) easy 2 clicks full copy or your macOS.
Well guys i think is more difficult remove the screen without breaking it that find it, I am sure that you can find a compatible “SMD Switch”. Just search for “SMD Switch” https://uk.farnell.com/panasonic/evqp7c0...-sw-spst-no-0-05a-12v-smd/dp/2860917
The only way is powering on the Device like @oldturkey03 says, modern mobile devices are encrypted and encrypting keys only work if some hardware is detected, like iphones they need CPU ID, NAND ID etc. If you take out the EMMC you can’t access to the information because you need the key to decrypt the volume. Old Android devices don’t have this feature by default and you can see the information like a usb stick device.