Rear Camera Power circuit--- How can I identify a bad capacitor?

The circuit in question: https://imgur.com/gallery/lyf7vla

I have several 6s+ that are suffering from the common water damage black camera/no flash issue. From a visual inspection, none of the capacitors look totally blown out, except a few that have some dark lines. Are these bad? Should they be replaced?

I’m pretty new to microsoldering, but any help would be appreciated, especially concerning how to test the caps.

Edit: This phone has had work done to the camera circuit before, apparently to no avail. also of note is the third small component from the right directly under the FPC, my schematic says there should be something there, but neither this board nor my donor board has one