Is it possible to replace the original logic board with a 1.67 board?

I think I've blown the logic board in my 1.5 GHz PowerBook 15" by letting the end of the display cable touch something on the board while powered on. (Is there a way to replace specific parts on the logic board?). I, however, am not 100% sure that the logic board is blown. I bought this computer off eBay, and it was reported to have had a bad display cable. I have not yet replaced the display cable. Could this be my problem? When the end of that cable touched the logic board, electricity arced and there was a pop. It doesn't chime when I press the power button now, as it did before. Logic board, right?

Anyway, my main question is if it's possible to stick a 1.67 GHz board in the PowerBook (bearing in mind that it is in the 1-1.5 GHz generation, and the 1.67 GHz had differences). Are they totally different animals? I look at close up pictures of the 1.67 board and it looks the same, but I don't know if it's exactly the same. I don't want to buy the wrong thing.