Deathstalker Ultimate needing a fix

Hello! My Deathstalker Ultimate has been dropping random keys or repeating keystrokes lately. I tried several things, and updating the chipset driver and the keyboard driver and firmware solved the issue a while ago. But it started again this week, more intense to the point that it was impossible to type anything, even a short password. I updated the drivers again, and uninstalled and reinstalled Synapse, but that didn't fix the issue. I tried using the firmware updater, but it updated the firmware and got stuck at 2% when verifying the firmware, resulting in an error "Firmware update failed." Now the keyboard is no longer working, the lights don't turn on and Synapse doesn't recognize it. The computer does recognize that a device was plugged, and shows a "Razer Bootloader" device, but typing doesn't work and the keyboard lights doesn't go on. How can it be fixed?