I like to get the light flashing on the remote and set it down close to the Roku device before I connect the power to the Roku device. I believe that's not the recommended way, but it has always worked for me. A couple of other things to try: If you have any other Roku devices you may want to disconnect the power to them so that they can't possibly interfere in the process. It may also help to turn off/disconnect your Wi-Fi. And finally, make sure you're using good fresh batteries in the remote. I've had batteries that would work just fine once the remote was paired, but couldn't get it paired in the first place.
One other thing that may be the most important of all, the 3810 uses a USB cable that contains the Wi-Fi module. If your USB cable doesn't have a bump in it then you'll never get the remote to pair.
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