Just purchased an arcade cabinet with the monitor inside no board (going to use PC with mame). The person I bought the cabinet from swore the monitor worked but couldn't show it because the power supply was out.

I got it home and since I will not be running a board with this I figure I don't need the power supply. I hooked up a power cord from the wall to the transformer thing that powers the monitor and marque. When I plug it the cord I can hear it get power (high pitch hum) and if all the lights are off I can see the tube neck lightly glowing orange. But no glow comes from the monitor (even tried playing with brightness on the extra board with the knobs for contrast and all.

I figured that maybe i needed a video signal for it to show anything so I cut up a vga cable carefully and wired up the composite sync, ground and r,g,b to the monitor board. turning on the computer produces no change in the monitor at all.

The monitor does however flash when I connect the power and disconnect the power so I am hopeful. I saw one possibly suspect cap on the monitor board that i attached a picture of, also of the model and short youtube video that shows the monitor when power is connected and disconnected.

http://www.youtube.com/watch?v=sRt5VePeqXM

Specs:
Chassis: QNIC CGM 2500 25" monitor
Tube: RCA A63ADT10X05
Input: PC with nvidia 6600GT vga out, broken out to composite sync, RGB and ground.

Thanks in advance for any help you can provide.

On your youtube video are you turning the monitor off? If you are it looks like that monitor is working. You could turn up the screen color on the flyback to see the picture glowing. I am just guessing but the monitor is probably CGA 15K signal and maybe the video card is higher and you probably don't have it wired right because I would think you would see something even if it's the wrong signal. I have never wired a computer up to an arcade monitor that didn't have a VGA input.