Well, I tried it. CEC, Anynet, HDMI control; neither the satellite receiver (HR24, I think) and the TV have ANY commands that even mention this.

What a bargain that was.

Happened 3x so far.

First time was on a 3tv matrix setup. Customer provided all TVs. Two of them were 32" and did not have discretes. What a PIA on programming.

Second was a 40" bedroom setup for a AirBnB. Was the old directv remote so I had to put in the directions to slide the toggle switch over to TV. Again major PIA

Third was a 32" kitchen TV, again PIA

If a tv responds to discretes, you can search by TV ON or OFF command. Say we search for OFF, with tv on:

1. tv
2. press and hold MUTE & SELECT for two blinks
3. enter 9 9 1, wait two blinks
4. enter 1
5. press and release TV OFF key
6. point the remote at the tv and keep pressing and releasing the CH UP key, if and when the TV turns off
7. press select to lock in code

Remember there are over 300 brands of tv, many with more than one code, give it time.

edmund, it's a bit weirder than that.

While in the DirecTV remote programming mode, I get a command that works. Then, when out of the programming mode, the command doesn't work. I've tried more than half of the suggested codes, and each one that works while in programming doesn't work. I gave up halfway through because, to test the code for real, I had to find a code that worked in programming, exit programming, and try the OFF button at the top right. Each time, the TV put up a message saying that function was not available. (The DirecTV DVR turned off correctly in every case.)

I've left them the DirecTV remote and the TV remote, without even checking to see if the POWER button works with the slide switch in the TV position. I think that making the client and various friends use the slide switch is a recipe for disappointment because someone will leave the switch in the TV mode and the next person along will simply have a TV that "doesn't work."

Now that I know there's no CEC or similar to turn on with these two devices, I'll probably go back and try ALL the preset codes, and I'll definitely try edmund's ON and OFF command method given above.

It could take me a week to get to it as we've moved on to other things at the house. I'm interested enough to pursue it, though.

FYI the DirecTV box DOES have HDMI CEC control. It is in the menu.

But that model Samsung TV does not appear to have it. Which is unusually for Samsung (they love their Anynet).

At this point, is it really worth it? Why not just sell them a cheap universal remote w/learning & macro ability. The only reason not to, would be if you needed the RF function of the DirecTV remote.
But I might still argue you've burned enough labor time screwing with this, to sell them a remote/RF base setup.

Brad,
Considering that I couldn't find CEC or HDMI anywhere, maybe "in the menu" is too big an area for me to comprehend. Where did you find it?

It's not something that doesn't come up in the menu if your HDMI cable is connected to a display that doesn't have CEC, is it? Stranger things have happened.

Duh or d'oh!

I'm not sure which.

edit: Then again, I looked that up. I think I'm more reasonable than the DirecTV receiver: It's under Display/Video and it's called HDMI Control.

I want my Display's Video settings set to POWER things up or not. That's a DISPLAY setting. Right.

Yeah, right. And HDMI works every time. And the industry made sure the technology was mature, and waited to introduce it until people had developed means to use it with great A/V systems having up to fifty feet of cable between the AVR and the projector.

The remote is not an RF remote. Turning on the DirecTV's HDMI control does not change anything. That's all the time I'm putting into it for now.

Remember I said the Samsung TV you have to work with, does NOT have HDMI control (which is unusual for Samsung).
So without the CEC protocol available on the TV, it doesn't matter if you turn the HDMI control on/off in the DirecTV receiver. It has nothing to control.