I have a barely used 25" Pentranic CH-288 monitor for sale. I'm pretty sure it has a switchable chassis for CGA/EGA, but I haven't tested EGA. The schematic is
here. It does have one issue: I can't get it to sync to CGA over a composite sync line, i.e. JAMMA. It works fine if I hook it up to my MAME cabinet w/ ArcadeVGA because that has HSYNC and VSYNC. Supposedly there's a way to get it to sync over a composite line, but I can't figure it out. I'm not a monitor expert by any means.
The monitor comes with power cable and 2 video cables, one for MAME, and one standard video cable for RGB.
Pick-up only. Asking $150 OBO.