Absolutely. Fuse is doing its job.
Quoted from etolisano:These are brand new boards and that seems unlikely but who knows. At least it would be under warranty.
Not if you have defective activation. It's not a manufacturing defect if the damage gets caused by the rest of the machine having an issue; that's going to vary with manufacturer and sometimes even with the retailer you buy it from. Some of the retailers will tell you to pound sand on *ANY* electronic issue after the sale.
If it was shorted and caused it to lock on, yes. When you first got the board, did it work ok until one of the pops activated? It could have burned out the transistor then.
Do what Bob says regarding the connector to know for sure - you're removing the activation path from the equation. Anytime a williams special solenoid locks on at power up, it's almost always a bad transistor/predriver transistor, because the special switches aren't supposed to be active in game over mode. (That's another thing that can be bad - the activation path, but that's less common)