Most likely suspect is the lighting FET(s), if those are dead it can be fixed. The "lit very bright" is the key, you were supplying it with way more voltage than the bulb was designed for.
Send it off the GGG, he fixes stuff like that for reasonable bucks. If he can't fix it, then you can consider the PS32 board. Since the board is most likely in the tender, there shouldn't be a big issue in fitting the replacement PS32 board in.