I would take the front cover off, get down to look under the unit and see if when it says SPK, if the pilot did light or not. If it lit and the unit continues to SPK, then I suspect the board. Remove the four screws on the enclosure and inspect board. You can remove the screws from the board to inspect the other side of the board for maybe a small dead animal. Here in FL we get lizards that crawl up in there and short out part of the board.
You can also listen to hear for a small click of the gas valve when it says SPK to see if the gas valve is opening the pilot portion. If you don't hear a click, then it could be the gas valve or the board. If you wanted to check the valve you would have to get a volt meter to see if the board is sending 24V to the valve to open it.