If it has never been serviced, your finding is not surprising. First, the electronics probably utilize a bunch of electrolytic caps. Many of these caps may have become "leaky" due simply to their age. "Leaky" means in an electronic sense that they leak DC voltage. (Capacitors should not pass DCV.) Leaky in the physical sense means they can actually dispel their electrolyte into the chassis, which can cause corrosion, etc. That's one place to start looking for trouble. Then a leaky cap could have caused damage to connected components, especially any integrated circuits. If you replace all the electrolytic caps, you may be lucky to have solved all the problems.
