Phone responsive but black screen: Broken motherboard or display?

Hello,

I come here to ask for some advice on my water damaged galaxy s20.

Back Story:

I was changing the battery on my phone and as was suggested in the iFixit guide, I applied alcohol to the battery area to loosen the adhesive. Unfortunately, I didn't read the label and ended up putting alcohol that only had about 40% alcohol. This caused me to unknowingly damage the phone.

Once I finished the install I turned the phone on and initially, everything worked fine. I went to turn on the camera and I was told camera failure and was sent back to the home screen. After half a minute or so the screen went black. I tried for a little longer to hard reset the phone until I decided to quickly take apart the phone again, unplug the battery and look for the problem.

After taking the phone fully apart I discovered some liquid in the sd card area. I dried it as much as I could and put everything into a bag with desiccant overnight. This morning I reassembled it and tried to turn it on but still the same problem. I then took the phone even further apart and found that the humidity indicator near the bottom of the phone also was pink (though I never saw liquid there myself). I also cleaned all the electronics with contact spray (made for electronics) and scrubbed with a toothbrush.

Problem:

Phone turns on, vibrates, makes noise, charges, takes touch input BUT fully black screen.

I don't know wether my motherboard or display is broken (or both!)?

Replacing the motherboard is not hard and not nearly as expensive as replacing the display but I also don't want to get a replacement motherboard only for the display to remain black...

Any help is greatly appreciated!