I followed the procedure as outlined on the Yamaha site. Tried 2 different usb drives. Held the the power and stop/start button along with the power button. Display reads insert the files
Disc. Then it just sits there with the usb drive flashing.

Anyone have an idea as to what I’m doing wrong?
Thanks,
JM

I don't remember holding the power button. Just the other two. The power button was a single push for me.

You MUST format the USB drive in the SX900. Then put the setup file on it. Directions are included in the download, but basically you just hold Start Button and turn it on and do what it says.
Of course unzip the download file.

I have the files unzipped on the drive. What other button besides the start stop button are you supposed to hold down?

Firmware Installation Procedure
Notice: Do not turn off the power of the instrument or remove the USB flash drive during this operation.

1) Download the firmware
a) Download the Zip file to the computer.
b) Connect the USB flash drive to your computer.
c) Extract the *.prg file and copy it to the root directory of your USB flash drive.

2) Connect the USB flash drive to the instrument
Connect the USB flash drive containing the downloaded files to the USB TO DEVICE terminal of the instrument.
Notice: Make sure that the USB flash drive is properly connected to the terminal.
Excessive force or incorrect insertion may damage the terminal.

3) Install the firmware
a) While holding down the STYLE CONTROL [START/STOP] button on the panel, turn the power on.
b) When the following message appears, press the [START/STOP] button to start the firmware installation.
c) When firmware installation is complete, the following message appears with the new firmware version. Press the power button on the instrument to turn it off.

What two buttons Dave?

Thanks guys...but the screen says “Please Insert the Install media” and the drive sits there flashing. Screen does not change.

Ooops - sorry it's ONE button "Style Start/Stop" I was thinking 2.

Try another usb stick to see if it that's the problem.
Sometimes they fail, even if it's not very often nowadays.

I’ve tried 2...but I’m off to work. Try again tomorrow.
Thanks guys,
JM