Not faulting you for trying the board. I completely understand. Most sellers frown on returning parts after they've been installed, but YMMV.
There are a number of potential problems that could explain your problem, unfortunately, I'm not sure you're going to identify the problem through parts swaps at this point.
As I see it, here are the most likely culprits in what I would consider the most likely order of probability:
- Faulty heating element (there are multiple ways an element can "fail" without complete failure. It could be or could have been heating without putting out enough heat.
- Bad connections in the lines connecting the heating element
- Something I and others here are overlooking or haven't had the ability to observe. It can be difficult to troubleshoot with the best information and first hand observations.
- Could still be a bad board. I'm not sure I understand what caused the fuse on the old or new board to blow. I wasn't quite following when you described what happened with the new board.
- Power supply issues. Unlikely, but it's possible that you have power at the outlet but its not "right". The rudimentary test of unplugging the refrigerator and plugging something else in only indicates whatever you plugged in worked. The only way to truly verify it's right is to measure the voltage on the outlet while the refrigerator is operating. Again, this is not at all likely to be the problem, but it is possible.
- Gremlins ;)
