Have SY77 since new and last year the last octave quit producing any sound on any key and a month or so later the bottom low octave did the same. When I contacted the service man he said that it sounded like dust had gotten to the two octaves and to take the keyboard apart, blow it out and spray contact spray on the two octaves of keys. I did but still not a sound or either octave. The middle octaves play the same as usual. Any ideas? Tried UK forum and they had no suggestions!
Welcome to the forum. The contacts may need checked. The Yamaha team will repair it for you - but you'll need to courier it to them and pay for any replacements/repairs. Another option is to contact your local music shop and find out who comes in to do their repairs. Get their number and give them a ring. Great keyboard if it's the one I'm thinking of. I had a DX7 in my gigging set-up for years. Sold it, regretted it and later bought a TX7 (the rack version). Really cut through in a live band situation with noisey guitars.