Where did you get the firmware you are using? The instructions are included in the firmware I linked above and they certainly include the USB instructions (To be clear, it is a laptop connected by USB, not firmware residing on a USB stick)
The fault is just stating again that the update failed.
Try the newest firmware from here.
I have seen quite a lot of failures with updates on Macs, if at all possible, try from a Windows device.
I'm attempting to upgrade my 6515 from s/w 65.10.41 to 65.21.41 using the firmware update tool on my mac running 10.13.3
The firmare tool runs and says firmware upgraded and I get 5 beeps from the printer but it sits displaying "An authorized user is making changes to this device, Please wait....” forever. If I switch the printer off and on from the front panel I get the following on the error report and the s/w is still at 65.10.41:
The software upgrade failed(017-759)
Solved! Go to Solution.