since it's a Wells-Gardner K7000 monitor, it can be any number of things causing it.
since I'm assuming it worked based on what you've said, there are chances that you might have the typical dead flyback + assorted other electronics. I'm not going to tell you to start ripping the monitor apart, that's asking a lot from someone that's new to this stuff, but I guess the real question is are you handy with a soldering iron at all? you'll definitely need to know how to use it in this hobby if you ever wish to do your own repairs. it's easy stuff to do, so it's worth knowing.
if you haven't done so already (assuming you want to attempt this yourself), you're going to have to learn how to discharge monitors. there's many videos on youtube that show how to do this. you really only need a flathead screwdriver (preferably a longer one) and a set of alligator clips (I actually cut one end off, stripped it, and wrapped the wire around a dedicated flathead and wrapped it in electrical tape

)
areas I'd check are the flyback transformer, particularly if the adjustment knobs are white, those had a high failure rate I guess, and can mess a lot of other things up. next in line is the "critical safety cap" which is located at C36, then there's the horizontal output transistor (HOT) that's attached to an upsidedown L-shaped piece of metal, and last is the voltage regulator in the corner, has 4 legs I think, also attached to the metal heatsink.
any or all of these can fail in the event of a flyback failure, which consequently (in my case AFTER everything got fucked up) will blow the line fuse.
how do you check these things? well, that's not for the faint of heart either. my advice is to post another thread asking for monitor repair help in whichever area you live in, perhaps another user can assist you live.
it's not hard stuff to do, but it's certainly psychologically brutal to get into.
good luck sir.