Repair guidance U40 organ

Hello, I'm new to the site and to organs in general. I was recently given a U40 and was very excited to add it to my instrument collection. The previous owner told me everything on it worked and he never had a problem with it. Alas, a few days after I took possession of it, my band was jamming to the song Sing Sing by the All American Rejects when suddenly the lights started flashing randomly and I smelled some hot electronics. It'll still make sound, though not as strong, and when the volume is cranked to 3/4 you can hear clicking from the speaker. I have some basic knowledge on electronic repair and was just wondering if someone could give me some pointers in where to start looking for the problem? What are some common problems and weak points in this organ's electronics? Thanks in advanced!