Making my SIR-T451 remote work with my Zenith TV.

It is possible that those buttons have failed, but a bit more likely the remote lost the codes for the TV itself... since almost everything the remote controls... is on the DVR. I apologize if I am guessing wrong in assuming other "TV" buttons (like INPUT) don't function either.

To re-program your remote to recognize your TV (like when the tech first set up the system) choose from the following receiver types to find the correct remote control TV codes for your Zenith.

Remote TV Codes for 722/622/612/411/222/211 Receivers
Remote TV Codes for 625/522/512/510/508/501 Receivers
Remote TV Codes for 811/381/322/311/301 Receivers

I could not find the code for my Sharp TV but the Code Search Method Worked.
1. Manually turn on the TV
2. Press and hold the Power and Mute buttons until the red light remains on.
3. Release the buttons.
4. Press the Power button to begin the code search.
5. Press the Power button repeatedly until the TV turns off.
You might have to press the button 100 times or more to find your code.
6. When the TV finally turns off, press and release the Mute button to save the code.

follow these steps below:

TV
RED + SELECT (flashes twice)
TV
0000
SELECT.

you owe me a pint!!
take care

Little Dish Fitter

Somewhere in it's lifetime, a user has set the 'user preference' to 'mute' while this channel was active. I don't know your specific set, but most TV's need a remote to work 'mute'.
Second hand set?
[A] check all buttons on TV for a crossed-out speaker symbol, or
[B] buy a universal remote and select pin for your set. Then,
Try these:
ZENITH - 000,001,004,023,038,058,059,064,073,121,135,136,153

I had the same problem programming my directv remote to recognize the ssc719c. What finally worked was programming AV1 (not 'TV') with the sylvania DVD code 20821. This allowed me to turn the tv on and off and change tv channels, but wouldn't allow me to mute or change the volume. To fix this, (at least in my case) you have to program your remote to recognize the volume and mute buttons in the AV1 slide setting. I assume other (non directv) remotes similarly disable the volume and mute buttons when the remote is not in satellite or tv mode. Anyway, here are the instructions that activated the volume & mute buttons on my remote: "Depending on how you set up your remote, the VOL and
MUTE may control the volume only on your TV, regardless
of the position of the MODE switch. This remote can be set
up so that the VOL and MUTE keys work only with the
component selected by the MODE switch. To enable this
feature, perform the following steps:
1. Press and hold the MUTE and SELECT keys until the
green light under the DIRECTV position flashes twice,
then release both keys.
2. Using the number keys, enter 9-9-3. (The green light
will flash twice after the 3.)
3. Press and release the VOL+ key. (The green light
flashes 4 times.)
Now the VOL and MUTE keys will work only for the
component selected by the MODE switch position."

To sum up: if you find a code for your remote that will turn your tv on and off, but doesn't seem to do much of anything else, it's probably the right code; your remote is probably set up not to recognize volume or mute inputs in AV1 or AV2. You change that using a remote-specific code that's probably found somewhere on the remote maker's website.

Did you try using the volume button *on* the TV rather than your remote control? If so, did it work? If it did work, then the problem is with your remote control and you should get a new one.

take a poop ans sculpt it into a new remote.

Oh, i would let it dry out in the sun for a couple days before attempting to sculpt, up to you.

Try changing the batteries. Most times the "tivo" buttons will work but the "tv" buttons will stop working when the batteries are low.

If you have done that, go back into settings and program the remote again for your tv, then give it a shot.

You have to push and hold down TV and Mute button (for 2 seconds at the same time), then release them at the same time, then push channel up until the TV turns off.  Be patient and continue channel up until the TV turns off.  When it turns off, then push TV again to lock the code.

You were doing fine, but missed to push channel up to fine the code.

The tv has lost the menu,in order for the menu to come up in the screen it needs horizontal and vertical sync,the syncs come from the secondary of the flyback and from the vertical Ic.Is rare but We have seen it happen,sometimes you also have an Ic called character generator and it could be bad.You will need the assitance of a servicer for this problem because there are voltages to measure and signal to trace.