Well, I got the generator running and everything checked out okay. Charger worked, engine ran great, generator made juice. The diesel can I had rigged for the test ran out of fuel, so I put more in and primed it up and just left it for about a week. I left the trickle charge on, just as it would be if it were hooked up to the barn.

So yesterday, I was getting ready to move it out of the shop and decided to fire it up one last time before taking it up to the barn. It cranked a few seconds and just quit. Traced the wires and found the circuit board was fried. I'm wondering what could have caused this. Now on New Years Eve, we had some really terrible wind and the electricity flickered a couple of times. Could a surge have caused this? If so, why did it even try to crank? Last time we had the electricity flicker I had to replace a power supply on the PC that was fried from a suspected surge. Is it possible for the charger to overcharge the batteries just enough to fry a board? Could it just be bad luck? And one last question, anyone know of a website that might have a board for this?

Type SD075-A164.OD18CBYYC

Here's the unit.

Here's the removed circuit board.

This is the panel that encloses the board.

Here's the damage. I'm not sure if I have the parts labeled correctly.

 And here's the back of the board.  I have a feeling this is going to be expensive.  I don't mind replacing a board, but I just wish I knew what could have caused this so it doesn't happen again.

Thanks in advance for any help.