MacBook Air will not charge, no sound from internal speakers, USB port

I have purchased this MacBook Air used. It has several problems and they all seem to be coming from the I/O board. Is that what I need to replace or is there another solution to pursue?

The computer receives power from the charger, but the charger light does not come on, nor does the battery charge.

The internal speakers are not recognized. They do not show up in the preferences and the volume cannot be adjusted.

Also the USB port on the same side as the charger does not work. The USB port on the other side is fully functional.

Is my assumption correct about the I/O board being bad? All the problems come from that area.

I also see evidence of the SMC having a problem. Fan running full speed at all times, no sleeping when the lid is closed. I have followed the steps to reset but there is no change. Could this be related to the I/O board also?