Hi Guiseppe,
I assume that you have correctly downloaded the S910 firmware updater to your computer, e.g. from here:
>>>
https://it.yamaha.com/it/support/updates/firm_psr-s910.htmlThen unpack the downloaded zip file on your computer, preferably in a new folder.
Make sure your USB stick is either formatted directly on the S910 or formatted on the computer in FAT32 format.Then copy the (7) extracted files (file extensions ".PRG" and ".prg") directly into the root directory of the USB stick, NOT into a folder on the USB stick. Be careful not to copy the folder from the computer that contains the files.
Connect the stick containing the update files to the
switched off S910.
Press and hold the STYLE START/STOP button while turning on the S910. (Do not release the button until the black display of the update tool appears.)
Follow the instructions on the display.
P.S.
Some sticks cannot be used for updates. This is the case if the stick is not recognized as a "Removable Drive" but as a "Local Disk" on the computer. Therefore, use a different USB stick if the problem persists.
I wish you success!
Best regards,
Chris