Once you put it in standby mode the Harmony should be able to operate it from there. Once you have it working with the OEM remote, check the device power setup and make sure it matches (discrete vs. toggle) and that the configured power commands work as expected in Device mode (manually send the power commands in Device mode to verify them). Next make sure the receiver is in the appropriate activities and select an activity. If the receiver doesn't power on or off as expected use the HELP button - this will resync the receiver's power state with the harmony smart state. After that it should work.