Can't adjust volume, someone knows circuitry?

Ok I repair ipods and phones, more of a hobby and makes some extra bucks. I have a problem and I thought I would try if some fellow ipod enthusiast can answer.

I bought a broken nano 5th gen 16gb, had a lot of water damage, I cleaned all the corrosion, washed it, changed the battery and it came back to life, everything works fine except the sound quality is bad and when I adjust volume it does nothing. It shows the bar and clicking, but the actual volume stays the same. It is not the jack, I tried few.

Can someone who knows his way around this motherboard point me in some direction? Something to clean again or reheat? Some faulty potentiometer perhaps? Thanks in advance