Backlight is unreliable, behaves intermittently
Hello! I have a laptop, serial F8V, that has an intermittent backlight -- sometimes it's not on when the laptop powers on, and sometimes it is. Sometimes the backlight doesn't come back when the laptop awakens from sleep. You can always generally get it back on, but it takes powering on/off, etc.
The board previously had some corrosion that was cleaned off, and previously was not powering on fully, and just showing a glowing sleep light. So that issue seems to be resolved, but now I've got this backlight problem.
The question is this: Would this problem more typically be the board itself, the topcase/keyboard assembly, or the screen assembly? I don't typically get a lot of the 15" unibodies, so I don't have a really strong sense of what the culprit would be. I vote that the board is bad, since it had slight corrosion (and unibody boards are generally so fragile anyway), but I thought I'd reach out and see if anyone has something interesting to add.