Yamaha P 70 Grand Piano/Voice button does not work

by Kaden
(Manta, Ecuador)

I got a Yamaha P 70 that was all in pieces. I re-assembled it according to an online service manual. The Demo function works well and I am able to select different voices while in demo mode. The problem is that the piano will not function in Grande Piano/Voice. Pushing the button and a key does nothing....nada. I have tried many online solutions without success. Can someone out there help....please.