Vintage Synth Repair

Hi,
I just joined. I found three nonworking synths and bought them for 
$30 each. A Prophet 10, Korg Trident mk II, and Roland Super JX 10.
1)The Prophet has some regulators in wrong. The 12v and 5V were 
backwards but the 12V should have been fixed voltage and had a 
varible regulator instead of fixed Vreg without feedback resistors. 
Hopefully that fixes that. There may have been some big voltage on 
the 5V circuit. I'm a little concerned because that reg open loop may 
have been 37v. It lit up though while wrong just no sound.
2)The Korg had a memory battery leak on the board and fried some 
traces. So PCB repair and new battery may fix that. I like my odds on 
this one. It lit up too but no sound.
3) The Roland has good Power supply but nothing lights up. The whole 
top LCD or LED plus all the buttons are out. I could appreciate 
advice or if anyone has a schematic would help. If I get one synth 
working I made a good purchase. I'm optimistic on the first two. They 
light up and look like they want to work.

Thanks,
Frank

I'll talk about my Hammond H-100 problems later.