Hardware Diagnostics for Unresponsive Phone

[MacallanNeat]

I've successfully disassembled my S22 Ultra after it took a hard hit (front screen) from a beach wave while filming. The phone stayed on and worked properly for about 5 minutes, then rebooted itself 3 or 4 times before never coming back on. No vibration when plugged in.

Nothing visually stands out as damaged and the LDI is white. Is there any method to testing the different hardware of the phone to figure out what needs to be replaced? I'm pretty tech savvy, so difficult/painful recs welcomed. Thanks!

[TheGalaxy]

Disconnect the battery
Hold all buttons together for 30 seconds
If not
Remove motherboard
Check for water
Use a hair dryer on all shielded chipsets
If not
Disconnect everything except for battery and screen cable and test
If not
Remove motherboard
Bath in ultrasonic solution
Dry and test
If not
Visual inspect with microscope for and capacitor, resistor, voltage regulator around the shielded chips.
If not, buy a new charging board or measure the voltage output of the charging board
If not
Take the motherboard out and desolder shield chips or by one and make sure they are dry

[MacallanNeat]

Thanks! What should be expected once disconnecting the battery and holding the buttons?

I forgot to mention that it's been a week, so I don't expect to see any water.

[TheGalaxy]

After 30 seconds of holding buttons, connect the battery and test.
Water will remain between component for a long time

[MacallanNeat]

Doesn't this appear to be damaged?? It's the motherboard connector to the actual battery's flex cable....

[TheGalaxy]

The picture is blurry

[MacallanNeat]

Better? Sorry, this is as good as I could get