The MX-650 does not like the codes for the Comcast X1.

Many codes took dozens of attempts to get working on the MX-650.

The Exit button just wouldn't learn from the original remote. I loaded the X1 codes into an old Harmony remote and was finally able to get the Exit button working.

The only issues are the Page Up and Page Down buttons. I couldn't get them to work. URC tech support suggested trying to load the codes from database into MX-850 and then try learning into MX-650. I'll give that a shot.

The good news is that once the codes were into the MX-650, they could easily be copied to another MX-650.

Anyone have experience with the MX-650 and the Comcast X1?

this is an issue with all remotes when learning the x1 codes.  urc had some trouble getting the codes, but they posted in the urc forum that they solved the issue.

if you are using IR, use Cable codeset 195
if you are using an RF base, use Cable codeset 202

if the codes aren't in your database, you will need to do a live update (assuming URC is still keeping the mx650 editor up to date)

I don't believe the MX650 uses computer programmable software. They once had a part called a PCL-300 used to archive and update these types of remotes, dunno if it's still around.

From their site:
PCL-300 PC Upgrade Link
The PCL-300 gives professional installers the ability to archive configurations programmed on either the MX-650 or the MX-350 remote controls so that they can be reused in the future without repeating the programming process. The MX-650 and MX-350 remote control's IR database and the operating system of each remote control can be updated whenever an improvement is available by connecting the PCL-300 to the Internet and clicking on the Live Update button.

Be careful of using PCL300, I had two of them fry two mx-350's.

MX-650 is not computer programmable. It looks just like the MX-850 but without the 3.5mm jack for sync cable. It replaced the MX-600 (which was the RF version of the MX-500)

I downloaded the code set 195 into MX-800 and will see if I have any better luck learning the IR for the last 2 buttons (Page up and Page down) from MX-800.

FYI, codeset 203 seems to be the one that works most consistently for us. Most of the codes in the various databases work fine - but may be sluggish or cause double press issues; stop/exit is the one sticking point. for each box its trial and error to see what combination will work best. 195 mostly works (except for stop/exit) unless this has been resolved in the newest ccp update (I know this doesn't help with regard to an mx650 - but if you have a ccp capable remote to help program with then it might).

As far as getting stop/exit to work on the MX650 you will probably be SOL. Time to recommend considering a new remote.

Update.

I was able to learn all the X1 codes into the MX-650 except page up and page down. Had to try multiple times to learn codes.

MX-650 w/ MRF-260 works well on Master X1.

Unfortunately, having problems with RF control on X1 slave box. IR works great, but RF is a problem.

Anybody else dealing with this?

Everybody. See post #6.

The last 2 X1 systems I did the master receiver worked with 202 codeset perfectly but the slave units didn't like 195 or 202, finally used 202 and had to turn down emitter to about half for it to function and the other had to relocate the emitter so it wouldn't go into overload( old base station non adjustable output), it's always a challenge with Comcastic devives!