To skip the back story, start after first paragraph.
Tl;dr=take off the back, blow out the dust, check wire connections, make sure no rust or corrosion on components. Dry clean what you can. Reassemble. I have pictures if I can post them.
I had this same exact issue happen to my friends PKO-1000. I was offered it before she threw it out. I read the first page of forums that come from google on “Baldwin PKO-1000” I was ready for bulging capacitors, ripped wiring, or acid corrosion.
there’s a wide box of thin metal that hold all the computer boards and components soldered to them; making up the magical sounds of the machine. One end of the box has the wire connections. Behind that is the speaker and power wiring w/boards and the slow blow fuse. That is also where you will be shocked by the posts of the power chord if working properly.
If you know how to use a screw driver and handle 8-10mm hex screws, and have compressed air for dusting, it’s simple enough to take apart safely without complex reassembly. Dust it, make sure connections are clean and secure, and look for corrosion around computer components. That may be all you need at first.