Possible parts that make the switch don’t turn on

Hello, I am new at this forum so I don’t really know anything on the electronics of the switch (it’s a disclaimer) . So one day I got between my hands the broken switch of one of my friend that won’t turn on (maybe, we don’t know, the switch doesn’t connect at the dock) and before it was broken, he smashed the screen because it was broken with the sun and he wasn’t using the portable mode of the switch . He also dropped soda on the switch (I don’t know when) but one day his switch said “goodbye” and no output except a blinking dock light even if the dock is fully working. When i got it, he was doing some clicks when plugged in. I cleaned the dry soda on the motherboard with a dry toothbrush and made the fan turn at high speed instantly after the battery was connected . I plugged it in back to try to charge it because the battery was at 2.7V. Some days later , i removed the motherboard to fully clean it (with the toothbrush ) and removed the cut ribbon cable of the digitiser and the backlight (for i don’t know how the lcd cable was already removed) and now no clicks when plugged in , just the blink of the dock saying that the switch is plugged in and some heat dissipating into the chassis. I don’t know if the digitiser ribbon was important to turn on the switch because it gives almost no signs of life.
I am thinking about if there is an important part, like the 2ds backlight connector , which is necessary for the switch to turn on .

A digitizer is not needed to turn a Switch on.