TCL Flip Left Soft Key not working

Hi!

After being in the rain for an extended period of time, my left soft key is no longer working. It did work initially after I dried it off, but is now not responding at all. The phone is currently off and there is no evidence of water anywhere. However, I have only taken off the back and checked under the battery, SD Card, and sim card. Is there a way to open the phone further to either dry off this part of the phone or repair any damage I have caused?

TL;DR: Hoping to find out if I can get my left soft key working again after some water damage.