Are you sure the update will solve this problem.And from where can I get the firmware.I miss my kb .I did a reset by holding C6.Does Yamaha know about this issue.
Yes, the Firmware update will fix that problem, IF your SX700 let you start the update. If NOT, probably only a Yamaha Service Center can help you.
Please download the update V1.04 by clicking on the link in ckobu's post above, and download also the Firmware Installation Guide from this site.
Unzip the downloaded zip file, and copy the contained PRG file onto a USB stick (directly into the Root directory of the stick, NOT in a folder!).
Connect the USB stick to the switched off SX700. Press and hold the STYLE START/STOP button while powering on the SX700.
If you are lucky and your SX700 accepts the update, follow the instructions on the screen. (Press the START/STOP button again.)
If the update does NOT work, the last option for you to try is a full Factory Reset. You can write me a Personal Message (PM) , then I will send you detailed information.
Best regards,
Chris