Is this water damage salvageable?

Most things are fixable but its a question if you have the tools and knowleage to fix them. What you would want to do is first run the board through an ultrasonic cleaner to remove all the corrosion. Then you want to get the schematics and board views for the board and begin testing every power rain the the machine. Once you find what rails are missing you will then need to trouble shot the circuit for that power rail and find the problem components and replace them.