Chosen Solution
So to begin with, as stated in the title I have an iPhone 7 that is no longer powering on, before this, I was replacing the screen as my brother had dropped the phone a few weeks ago, but just the other week the phone died and stopped charging and, I just left it down to the battery as the phone is around 4 years old but as the new screen and battery arrived nothing was working, I had been told by my mum that he had the phone in the bathroom while the shower was on and that lined up with what I found on the inside as there were wet parts, so I took some isopropyl alcohol and did as through of a clan as I could and found corrosion on the underside of the logic board, what I’m wanting to know is, there any other things that could be stopping the phone from turning on, take it into a phone repair shop or should I just accept that the phone is fried.
Your phone will not be fried. A reputable repairer should be able to get your phone working but depending on how much and where the liquid went they might not offer warranty as liquid damage causes the pads under the IC’s to slowly corrode and oxidise.