Chosen Solution
Ok we swapped the LCD with a known working LCD with True Tone and Webcam enabled. After we installed it on another Machine it was disabled and no True tone anymore. We took the original LCD back off and put it back on the Machine it originally came from…now True Tone and the Webcam is disabled on this machine as well! Can someone explain why is this happening? People are saying replace it with a known working LCD oem from Apple…well we just did that and now both screens are disabled. What is going on here?
Yep! Apple updated the system firmware on us so now you can’t swap displays any more! Your display has a ID which your system will only recognize. This ID needs to match and if you put a different display on and the ID is different it won’t accept it, now the real nasty! The system will loose the original ID so if you put the original display back on it won’t recognize it either again! All I can say is - THANK YOU APPLE!! NOT!! Such a bonehead action on their part! You’ll need to visit an authorized Apple shop to see if they would be so kind to recalibrate the display. Such an easy fix on Apple’s part to offer the needed tool or even program the EFI (BIOS) to allow calibration. SUPPORT the Right to Repair movement Apple needs to breakout of this mind set! Update (03/17/2021) See if resetting the SMC fixes the keyboard backlight How to reset the SMC of your Mac Otherwise you’ll need to check your cable connection for damaged pins on either the cable or logic board.
The information Dan posted is incorrect. You may have damage some lcd connector pins while replacing or your OEM screen is of poor quality. All screens for all models before M1 can be replaced without losing any functionality. True Tone will work. I have just replaced a 2019 16” model. Only M1 models have the LCDs paired with the Logicboard. If the lcd is replaced, True Tone will be disabled. FaceTime camera will still work though.
