Hello Sergio68,
As other members already undescored, an LCD 'off-the-shelf' replacement kit for the failing HP 3582a CRT seems not easily available.
So I guess that if you want to upgrade with LCD you will have to build that kit yourself. It is far from an easy project and I also doubt that anyone will do it for you. Tweaking such a conversion kit needs to have the video signal available. This means that only people who also own a HP 3582a would be able to do that.
As an alternative, it would be possible to digitize the video signal(s) and replay it with a powerful (multichannel ?) arbitrary generator. But this kind of stuff is not that common among electronic hobbyists.
I would suggest that the first thing to do is to catch the service manual to find where the video signal(s) are located and then open your unit and probe this (these) signal(s) to know their exact shape and frequency.
Even though I have very limited video knowledge, I would say that a good start would be to determine these features :
[video gurus, please correct me if I'm wrong]
- CVBS or RGB signal
- if CVBS, only luminance or is there also chrominance (color information)
- line frequency
- frame/image frequency
- interlaced image or not
- sync pulses (separe signal; mixed with CVBS, sync on green, ...)
After that, you can have a look to
this thread started by @DC1MCT, where @Trantraton (from Toulouse, France) works now for weeks to program a video processor/scaler in order to replace the old CRTs of Advantest SA.
Helped by very skilled members on this forum, and after 6 weeks of harship, some encouraging results did show up just very recently (actually this week).
But at the beginning, he also asked for help and nobody had an 'off-the-shelf' answer for him. He had to spit in his hands and devise himself an LCD kit for the specific requirements he has (as far as I remember : RGBS 15,8 kHz interlaced).
I think you will have to follow a similar track.