Water Damage, still usable!

@jacobfromerth my number one recommendation would be to start disassembling your laptop. Use this Dell G15 5515 Service Manual to work on your laptop. Remove the motherboard and then it's time to clean it. You must remove all EMI shields. If you do not remove those, you might as well not do anything. After you removed those, clean the whole board, connectors and all with +90% isopropyl alcohol. Follow this guide It was written for an Apple iPhone3G but all the points are still pertinent to your motherboard as well.phone. While you clean your board, check for any obvious damage, like burned or missing components etc.

Until it is cleaned, everything will only be a guess. Post some well-focused pictures of your motherboard with your question. That way we can see what you see iFixitでの質問に画像を追加する方法 and hopefully we can help you getting this back to "normal"