Still not working after replacement.

I have replaced the power/volume flex three times and I'm still having an issue.

The on screen volume indicator stays on at all times, saying that the volume is off. When I go into Settings>Sounds, and then turn the sound all the way up, it just goes all the way back down, automatically.

When my customer brought in her device, she said that the volume and power buttons both stopped working at the same time. And after replacing that flex cable and doing a reset on the device, I'm still having this issue. I assume this might have something to do with being water damaged, due to the fact that the water damage indicator on the head phone jack was bright red.

Any ideas?