TV remote control issue

Entendu. Je suis prêt pour la traduction.

It often works, not always, and generally not very easy.

I have accumulated documentation that often allows me to provide a solution. But without the brand and model, ... I don't have a crystal ball!

By going to http://www.sosremotes.com/, click on Equivalent Remote Controls, then enter Toshiba and your incomplete reference: SJ-
You will find 2 references SJ-3419 and SJ-3429 for which there is a remote control no. 91 73 67 58. It is pretty certain that this remote will at least work for the entire SJ-34 series... and therefore for your system, but it would be good to confirm this with them by phone.

Equivalent remote control means it behaves like the original remote and therefore only controls the device it was designed for and those of the same series. It is not a remote intended for multiple devices.

But are you sure that your system's remote control still works?
The fact that you can't use several universal remotes makes me doubt that. Unless these remotes are not intended for "Audio" systems, which is quite common. Do they have that button?