Chosen Solution
I spilled a little bit of coffee on my MacBook Pro and after 3-4 days the keyboard started missing around and I was not able to log into my laptop. A week later I reassembled all parts, cleaned up all the mess with a contact cleaner and a brush, and replaced the keyboard assembly. When I turned it on, the system would turn on, but the screen wouldn’t. I hooked up an HDMI cable to check if it was functional and everything seems to work great on the TV and keyboard is fully functional as well. I re-checked all plugs and connections and checked for corrosions, and found nothing :( I read on an answered question to use P+R+Opt+Command method, but that did not work either. You can see the screen (while it’s still black/dark) dimming but it doesn’t light up at all if that makes sense. Disclaimer: I am very new to this
From your description is sounds like the backlight is out but that the display is otherwise functioning. Inspect the conditions of the pins on both the display cable and the receiving port on the logic board. Do any of the pins seem darker or misaligned? If so it’s possible the backlight power pin is damaged. In some cases you may be able to clean it with alcohol or realign it with tweezers. I would also recommend carefully reseating the display cable multiple times to see if it’s a connection issue. Best of luck!
