Chosen Solution
I have three dead iphones. One 3gs, one 5 and one 5s. They all have dead logic board ( they wont turn on ) due to water exposure . Is there any method of extracting the photos from those Iphones?
Your 3gs can use the chip off method but 5 and 5s will require the phone to boot into the operating system before you can recover anything as the NAND chips are encrypted unlike the 3gs.
You’ll need to take the phone apart , clean the board and connectors with isopropyl alcohol, and use a soft brush to lift any corrosion off the parts. Then you may have the chance to getting your photos off the phone.