If the internal u-Blox NEO M8 series GNSS receiver is no longer working in an FC-6000 or FC-5000 unit, some possible solutions are as follows.
Disable, then enable drivers
Tap and hold (right-click) on the bottom left Start button, and then select Device Manager.

Tap on Sensors > u-Blox GNSS Location Sensor, then select Disable device, and then tap Yes when asked.

When asked if you truly want to disable it, tap Yes.
- Once it has been disabled, repeat steps to enable the device.
- If needed, follow the same steps with Device Manager > Ports (COM &LPT) > u-Blox Virtual COM Port.
- Once both drivers are enabled again with no warnings, verify the GPS function.
Note: Drivers for the internal GNSS (GPS) receiver in the controller install automatically through Windows Update.

Hard reset
Drain all power from the internal receiver to reset it. Follow these steps:
- Close running apps, then tap on Start > Power > Shut Down. Wait until both the screen as well as the red LED turn off (which can take a minute or two).
- Press and continue to hold the hardware Power button for 20 seconds (even as the red LED starts flashing rapidly at 10 seconds then stops at 17 seconds).
- Attach external power supply.
- Briefly press the Power button again, then wait for the unit to complete booting back up.
- Test the GPS function.