How to fix a psvita with fanta in it

Trying to charge or power up a gadget that has suffered from a liquid spill is the absolutely worst thing you can do, short of banging it with a 5 lbs hammer. Plus, water is bad, soft drinks are worse.

Before attempting to use or recharge a device that has had liquids spill into it, you'd have to take it apart and clean it. If the liquid is plain water you might get away with just letting it dry out, but soft drinks leave sticky sugary residue that never dries completely and has to be removed before you attempt to use the device again. If the device's battery is removable, it should be taken out ASAP. If the device has an internal battery, the device should be disassembled and the battery disconnected at the first opportunity.

There isn't a specific iFixit guide for cleaning your psvita, but there are many guides that show how to take it apart (and put it back together), see here:

PlayStation Vita

For cleaning, I recommend the use of water and a toothbrush to get rid of all the sugary goo. Demineralized water (also called distilled water) is better than tap water, especially for the final rinse. Let the parts dry out thoroughly before putting things back together.