Slight water damage but was working

My phone slid into my bath after it had drained so it was like a small puddle left.

Got it out quick and dried screen and in battery area. Forced excess water out by shaking.

The phone was still working normally apart from the speaker, which was intermittent.

Tried to lock it again but power/lock button didnt work. Home button still worked unsure if volume buttons work.

Stupidly i took battery out, to get the inside backing off to dry it more. once dried tried to turn it on again, only then realising power/lock button wasnt working.

Tried plugging it in to charger but USB isnt working either.

I know the phone is working i just want to be sure before i take it to get fixed orbuy parts to do it myself. Thanks in advance.