I just purchased a Roland TR-707 from a nearby flea Market, I cleaned it up and plugged it up but no power. I know it takes a 12v adapter. and also 2 aa batteries. What do you think the problem is?
I hope this does not sound unpolite, but:
I think the problem is, that you don’t have a volt meter at hand appearently and you are not able to read a circuit diagram.
try antoher power supply and make sure its got the correct polarity. if still no power i would try and solder the center pin in the 707 it may be loose (alot of laptop computers do this)