View and Download Korg POLY-61 owner's manual online. POLY-61 Electronic Keyboard pdf manual download. Dutch Light & Sound Engineering D.L.S.E. / Synthrepair. Home: Synthrepair I have a Poly 61 with leaked battery that corroded some components and traces, which I would like to repair. All the traces that I have checked still conduct, but there is some visible damage and I want to stop corrosion from spreading any further, my plan is to dissolve the coating of damadged traces and then remove the corrosion from them and component legs.