CRT TV with sound but no picture

As I mentioned earlier, I no longer have a VCR to transmit a signal. I tried using my Neufbox, connecting the antenna jacks (from the wall to the Neufbox and from the box to the TV), but it didn't work (in fact, I didn't even know if that could yield anything, I'm not competent in this area). Can I send a signal from my computer (I have neither a VCR nor a DVD player)?

In any case, thank you.

No, on a CRT TV, you shouldn't send digital signals because it won't work
including through the antenna cable of the Neufbox, which carries the signal in digital form; you need to send an analog signal
otherwise through a modulator (but you won't find that at the local store or even at a big retailer)
at first glance, based on what's written, I would think it's the "monitor" mode that has failed and not necessarily the tuner (but since digital, the tuner is useless)
as for getting it repaired, even for an association like "Emmaus" or a training center, it's not guaranteed they would take it
it's up to you to decide.

For the old annoying one, we cannot send a signal via the antenna because currently the signals are digital and not analog.
For the TNT decoders, it is only a digital tuner that converts to analog
and whose output is in SCART.
The antenna, on the other hand, receives and sends in digital.
There you go.

Thank you Nico,

I no longer see the snow so I think it is dead and I will let it rest in peace.

At the back of the TV, there are 2 Scart sockets (ext1 and ext2), 1 antenna socket, and 2 RCA audio sockets (red and white).

Yes, Nitram, because it's no longer on the manufacturer's website (manual), so in my opinion, this TV is over 10 years old.

the only way I know to do a quick test of the tube (if the AU function) is not working anymore is to connect a VCR (VHS) and send the signal from it via the antenna socket
if the tube is okay you get a picture return
if the tube is not okay there’s nothing
in principle in AU or AV mode you shouldn't have any snow
so are you sure you are pressing AUX on your remote?

not found his product sheet

Well, I no longer have a VCR nor a remote control, by the way ^^ ... but I'm on AUX since I can catch the sound from the channels of the box.
I think I'll throw it away, but I wanted to get confirmation that it's indeed dead.

If I'm not receiving any image from the box, is it normal that I can still see the channel numbers (e.g., ext1, ext2, 1, 2, ...), the manual TV menu (volume, picture)?

In any case, thank you very much for your help.

Yes, it's normal; this kind of information doesn't go through the same circuit
(e.g.: if the tuner is out of order, you will always have the channels displayed, but you won't have any picture feedback).