That is mostly what my blog has become, examples of some of the board repairs over the past 6 years.
It really depends on what is actually wrong with the device.
Not all things are fixable, for example: a failed CPU from extreme overheating.

http://www.freelancetech.info/blog/2025/10/5/playstation-hdmi-repair
http://www.freelancetech.info/blog/2025/8/27/macbook-pro-a2338-not-charging-battery
http://www.freelancetech.info/blog/2025/2/1/bad-capacitprs
http://www.freelancetech.info/blog/2024/2/7/xbox-series-x-no-power-but-power-supply-ok
http://www.freelancetech.info/blog/2022/9/30/panasonic-toughbook-fz-55-no-power
http://www.freelancetech.info/blog/2022/9/20/a1534-no-power-faulty-cd3215c00
http://www.freelancetech.info/blog/2021/8/14/gaming-pc-build-fail
http://www.freelancetech.info/blog/2021/5/3/a1932-no-power-liquid
http://www.freelancetech.info/blog/2021/2/15/acer-laptop-corrosion-from-ants-making-their-home-inside-the-machine
http://www.freelancetech.info/blog/2020/9/13/macbook-board-repair-a1466-liquid-damage-no-sound-system-running-slow

Liquid damage in particular is very dependent on how much liquid, how extensive is the damage.
If someone attempts to clean liquid damage with something like WD40 and then reconnects power you can guarantee that will cause more damage spread out over a larger area and make my life more difficult or the device uneconomical to repair. Please Don’t