Screen brightness is very dim after boot and no KB backlight
I have a 2019 MBP (A1989) that often displays full brightness on boot (Apple logo) and then dims to about 50% brightness. The mac shows that it is displaying at full brightness in macos but the keyboard doesn't illuminate at all, the TB buttons for the keyboard backlight won't change anything,
The option for 'Automatically adjust brightness' Is missing in settings.
Everything else works: the webcam works, and all the wireless antenna seem to work fine. I get the sense that the ambient sensor isn't working The same issue as:
The thing that is different for me is that the screen is the original.
I'm wondering if this could be anything else but the ALS? or if there could be any software that could spoof the light sensor to 100% all the time. The only Mac display I have is annoyingly from a 2017 Mac that apparently will work but with reduced brightness as the ALS isn't compatible...
Is it new display time? Are there any cables or resistors I can check? I'm just trying to avoid paying for a new display if it's not going to fix anything!
Many thanks all!!!