This ECU didn't look all that bad on the top side. There was, however, some evidence of prior rework on the top side that had been (sloppily) removed, causing shorts. And, of course, the ECU didn't work at all. So we decided we'd better check the bottom side before giving the customer a complete estimate. This is what we found.
That was the “before” shot. Here's the after. This was easily 90 minutes of rework.