I purchased the FLIRC IR sensor and cable to use with the FireTV. I also purchased the Inteset INT-422-3 Remote as a source for the FireTV codes. I set up the FLIRC, and memorized the commands from the Inteset remote, and that all works fine.

Then I set up the MX 850 to learn the commands from the Inteset remote, which also seemed to work correctly. However, when I try to use the MX 850 to control the FireTV, the response is intermittent, erratic, and generally flakey, so as to be basically useless.

Can anyone offer a possible solution? I remember long ago using the codes from a Pronto, and converting them to the MX 800. Might this provide a more stable setup than learning them? Do the Fire TV codes exist for Pronto?

Thanks for any advice from the forum.

There isn't Fire tv Ir code in any remote. So you can use any code set from any remote when using a FLIRC. So take the Interset out of equation, just use a code preset already in the mx-850. Some code that's old, say the Sony cd player code, its been around since 80's.

With the FLIRC (at least the original version), I've found that Panasonic codes work best for responsiveness and reliability. Way better than Sony, which had been my first inclination.

you are completely missing my point. First of all, edmund, the remote codes are on the Inteset remote, and second Daniel, using any other brand of codes will not operate the Amazon Fire TV. The codes work fine when sent by the Inteset remote, but not after they have been learned by the MX 850. I am trying to find out why the copied commands do not properly duplicate the original commands from the Inteset remote.

Richard, there can be many reasons why the learned codes have erratic behavior. Consider these tips for getting a clean learned ir signal:
[Link: remotecentral.com]

What edmund and Daniel were trying to explain, is that you can avoid this learning process altogether. How the FLIRC device works is that it emulates a USB keyboard. When it gets an IR signal it recognizes, it basically "types" the corresponding key into the device that it is plugged into. You teach it what key it sends when it sees a specific IR signal.

So for your MX-850, you can create a FireTV device and assign any IR codeset (one that doesn't match other devices in your system) to this FireTV device. Both edmund and Daniel have made suggestions for a good device. On my mx-780 and mx-990 remotes, I assign the Aux 001 from the URC database as the codeset for FireTV.

Once you have an IR code set assigned to the FireTV device in your remote, then you use the Flirc application to program each of the IR keys to the appropriate keyboard command for FireTV. I use the media keys for transport control but I also uses an extended list of keyboard commands for other functions within applications like Kodi (subtitle, audio track, audio delay, etc.).

The advantage of this method is that the codes in the library are usually very clean, repeat properly, etc., and completely avoids the IR learning step. Hope that helps.