Water damage gets progressively worse over time. The fact that everybody waits until there is a problem rather than having it cleaned by a professional immediately while everything still works, is why they are such a pain to deal with later on, and why i only offer data recovery on them.
It has now gotten to a point where something, somewhere, has corroded to a point where the BB CPU is not communicating (which also results in both error 53 and 54, and well as error -1).
The issue is that the solder underneath "something" now needs to be replaced, and this could vary from the BB CPU which has hundreds of balls under it that are about 0.2mm wide, to the BB PMIC that provides the BB CPU power, to any number of cellular transceivers or amplifiers ect that have a short underneath them. All in all the issue could be with any one or more of more than 1000 balls of solder
The catch is if someone is to reball the BB CPU, PMIC, and all the cellular ics, theres every chance next week it wont have backlight, wont turn on, the cameras will stop working, the touch, ect ect.
This is why its important to address water damage before it becomes a problem.
In short, its probably a lost cause, but you can try seeking out help from a board level repair technician on the link on my profile (there are techs from different parts of the world there). I personally wouldn't offer anything beyond data recovery though, and it sounds like right now it works enough to get the data anyway.