The folks that sold me the cab explained that the monitor did not have the required panel (below the tube) to run the monitor.
It sounds to me like your monitor is missing the chassis (mainboard), and thus isn't going to be hooked up to much of anything.
A game usually ends up without a chassis for one of two reasons.
The tube went bad, and they robbed the chassis to repair another game with a good tube.
They took the chassis out in order to repair it, but never put it back in.
Easy way to tell if you have a chassis in there is this. Somewhere there should be a large plastic cylinder (smaller than a soda can, but bigger than a roll of quarters) with a couple of knobs on it, and a red wire running to the suction cup on the tube.
If you can't find that part then you don't have a flyback, and if you don't have a flyback then you don't have a chassis (if just the flyback was missing it would be obvious where it was removed from).
There should also be a small square circuit board that is attached directly to the back of the tube (the neckboard) with several sets of wires that run to the chassis.
Finally, the monitor probably also has a remote control board. It sounds to me like the only thing yours has is the remote.
Basically, if you still don't know what I am talking about. Your monitor is like a car with no engine in it. It isn't going to go, no matter what kind of gas you put into it.