CRT to LCD

[Cicada]

Hi

We have an old CNC machine. The small orange monochrome CRT display broke and we are unable to source a replacement.

The idea crossed my mind that one can possibly recreate a signal to drive an LCD display from the X Y steering plates to the CRT tube.

I would like to know if it is feasible or are anyone aware of a project where someone have done this?
Maybe there is even some commercial products available.

Or is it a crazy idea?

EDIT: Or maybe not the X Y steering signals to the CRT but rather some signals coming from the controller to the PCB that sits on the back of the CRT that generates the high voltage and the X Y sweep signal.

Cicada

[Haenk]

It's probably not an XY-signal, but somethign like CGA/EGA. There should be converter available.
Maybe you can check the machine for the output generation (maybe an ISA card or something like that).

[Cicada]

Ok so I will have to check if it is EGA / CGA type signal coming from the controller / PCB to the CRT's board.
Then get a EGA / CGA type signal to whatever converter. One might even go to VGA for an external display

[SeanB]

Standards converter is what you should look for.

Try this from amazon this once you find what the display actually uses.

https://www.amazon.com/Atomic-Market-Output-Converter-Arcade/dp/B078HH526F

A few pictures of the CRT, the board powering it, and the connection to the PC that drives it would help, especially the connector that handles the video, and if possible the card inside the computer as well.

[Terry Bites]

LCD screen kits with VGA type inputs are avialable from many sources.  eg https://www.buydisplay.com/catalogsearch/result/index/?interface=716&q=VGA
You may need to convert CGA/EGA to VGA. Arcaade game conversion boards are easy to find eg https://www.amazon.co.uk/Mcbazel-Arcade-Converter-Monitor-Projector-Black/dp/B078ZDTLBJon ebay. You'll probably spend well under $100 do the job.

[coromonadalix]

yep

just need to figure out the video signal source ...

[reboots]

Can you describe the make/model of the CNC machine, and the controller if it's a different brand?

You might try posting your question to the Practical Machinist forum. It's not an uncommon problem with older industrial controls.

https://www.practicalmachinist.com/forum/

For example, here's a thread on converting a specific Yasnac brand controller to LCD:

https://www.practicalmachinist.com/forum/threads/crt-to-lcd-conversion-on-yasnac-lx3-mx3.384290/

[CaptDon]

Most of those monochrome units were not exotic. Polar Mohr for example used standard N.T.S.C. monochrome. Thermotron and others simply use 3 wires plus common ground at the N.T.S.C. / C.G.A. signalling rate. you have V-Sync, H-Sync and Video. Some are even simpler, Composite Sync on one wire and Video on the other and a common return. Some of the color stuff had a weird Green+Sync and it was designed so the Green+Sync could drive a normal N.T.S.C. monochrome monitor if the video card was jumper selected to act as such. Many of the old separate sync monitors also included a 'phase adjustment' for horizontal centering to correct for horizontal sync timing since some H-Sync video card outputs looked more like a squarewave.