Bubbling on power supply circuit board?
I'm currently working on a mid-2010 i7 iMac that had exhibited signs of potential logic board failure (intermittently not recognizing installed RAM and beeping during POST, random self-restarting if you can get it to boot, etc).
In the midst of replacing the board, I noted that there is a substantial area of bubbling on the underside of the power supply board (see attached picture). I have seen similar bubbling on much older circuit boards (for example in 1990's BOSCH Motronic ECU's in cars) that would indicate a failure. I assume that's true here as well? I'm not familiar with how these circuits are produced, so I figured I would ask. Thanks for any help you can provide!
Is this a good question?