firmware update fail

Hello I did the firmware update to the printer dell 1230c using windows 7 32bit , by using the firmware assistant once it was finish the printer got disconnected automatically as this was done via usb connection and the printer  was rebooted and now the printer is not recognized in any of tree computers shows as device unknown and on the printer only the light from the yellow toner indication light is on nothing more happens when turn on or off. what went wrong any suggestions to solve the problem thank you