How to test bad capacitors on logic board

Hi everyone, I've been repairing phones for a while and have recently started offering water damage repair with an ultrasonic cleaner. We get plenty going again but some have missing functions and some just won't turn on at all.

I'm getting into BGA rework and have repaired several logic boards so far but that was through trial and error with the capacitors and it took hours to fix each one.

I've read that you can test the caps with a multimeter which I have done by testing continuity but it seems like more than half the caps show continuity even on working boards. So is there a definite method to check a bad cap in the circuit and does it make a difference if there is a power supply to the phone?

Thanks everyone