Korean-made (duh!) quad-sync (standard, medium, VGA, SVGA) monitors. Digital control with OSD, dynamic focus, EDID, the works. Really awesome monitors... when they work. Usually has a Samsung tube, occasionally an LG.
Service manual here.
Model number is simply KT-xx14(D)(F), where xx is the screen size. F, presumably, means a flat tube; D means dual focus.
- KT-3414DF (somewhat uncommon; it's rumored that these were a special commission made for Andamiro and only used in Pump it UP and In the Groove 2 cabinets. Likely, as the PCB is marked KT-2914, and they certainly haven't been found anywhere else.)
For whatever reason, these monitors fully support DPMS. You can turn them soft-off the way you would a newer consumer monitor -- by grounding the connector shell without sending a signal. Maybe it was intended that they'd make a consumer version at some point.
This chassis is a bit unusual in that the heater voltage comes from a dedicated rail on the power supply, instead of the flyback. Of course, this means the flyback is special... and hard to find. New/NOS dual focus flys are not available period; your only hope is to find a donor chassis. All sizes use the same flyback, and single focus chassis have shipped with dual focus flys and the second wire left disconnected, so that helps.
Switch mode power supply; 90-264V full range.
- Flyback... yeah. If the picture is really unstable in both directions, you might want to just get a new monitor.
- EEPROM corruption. Turn up the flyback screen voltage until you get a little bit of raster glow; if you're a little lucky, you'll get a faint image as well. Turn it off, then back on while holding UP on the remote board. Then press MENU. This will get you the factory OSD menu. From here you should be able to fix the picture. Check the color temperature setting in particular.
- Cold/weak solder joints. In particular, reflow T101, C728, C727, C709, C705, C702 (source)
- Bad capacitors. A lot of these chassis came from the capacitor plague era. Swap ALL electrolytics, using the part list in the service manual as a guide. Even if the monitor works, you might want to swap them anyway. Bad caps can kill other, more expensive components.