Yes - And each case is different, so here we're theorizing because, as you pointed out, the OP hasn't come back to give us additional information.
But it is often this type of discussion thread that makes one think and brings out a lot of opinions to consider. A good way of 'calibrating' ourselves and our perceptions. One person says "It's easy, oxidation is the root cause", while another (in this case me) says "No, oxidation is the
effect of a cause".
We may go around the tree a bit but it makes one ponder how to determine Root Cause. I used to teach a class in it and even to today there are times it is difficult to assign a specific, individual Root Cause.
I do remember my first experience in Root Cause analysis almost 30 years ago. It had to do with component failure on a 3 layer hybrid printed circuit card. We didn't realize what was happening until we did thermal analysis of the card and found an upstream component was heating up and spiking the voltage on one leg which killed a downstream IC. We had to get a design change to get the up stream IC replaced with a more robust one.
Each Root Cause Analysis is like a detective story, but the Root Cause is never (at least so far in my experience) the Butler....