If you are experiencing issues using OOBM, try the following troubleshooting tips:
Reseat the connectors.
Disable and re-enable the Serial Redirect feature on the Ericsson Cradlepoint router.
Ensure you are able to access your device’s console directly through the USB-to-serial adapter.
Check the RS232 settings on your device and make sure they match.
Reboot the hardware, including the Ericsson Cradlepoint router and its client serial device.