I'm trying to pair an old-style BT box remote control with my 90-year-old dad's new Panasonic HD TV, so he can control the volume on the TV from one control. But it won't work and I can't understand why.
I've followed the pairing instructions (see below), holding down the two buttons at the top and entering the Panasonic code (3846) - the remote appears to accept the code (flashing 3 times). I then press and hold down the TV on/off button as directed, and the light flashes intermittently, but the TV does not switch off as it is supposed to.
What might I be doing wrong? I have tried resetting the remote but that doesn't seem to have helped... any advice much appreciated!
Does this extra info from the online instructions help?

That seems to imply that it will cycling through some timing or other setting until it hits the right one.
I should have said - have held the button down for well over a minute and still nothing happens
Odd question but does he have a soundbar by any chance? Reason I ask is I set up a Firestick for my neighbour recently & had very similar issues pairing his Panasonic TV to its remote. It only worked after I moved the soundbar well away from the TV's IR receiver. The Panasonic remote worked just fine but the Firestick remote wouldn't until moved the soundbar. I have absolutely no idea why though.
No - I can't see anything obvious that might be interfering. The BT remote otherwise works fine controlling the box (and the Panasonic remote controls the TV fine as well)
Had this problem with a neighbours box. The BT instructions you followed have missed out a vital step. At step 4, when you’ve turned off the TV, you then need to hold the “OK” button down until the blue light goes out on the remote . It will then work the tv ok ( usual incompetence from BT ).
This thread is three years old so hopefully those that have posted will have a resolution by now and you will most likely not get a response from the OP of the thread who has not been on the forum since the date he last posted on the thread.