I'm very new to any sort of electrical wiring and ran into a problem while trying to convert an old cabinet to MAME. I think the original power setup was wired incorrectly. Power went from the wall to the power switch, from the power switch to a fuse, from the fuse to a power supply. The power supply split power to the circuit board, a few lights, and the monitor. There was a transformer sitting in the cabinet, but it was not connected in the circuit at all, so power was going straight from the power supply to the monitor.
I pulled out the circuit board, disconnected the lights, pulled out the power supply, and put the transformer back into the circuit. So now power goes to the switch, then to the fuse, then to the transformer, and then to the monitor. I think that is right, but like I said, I'm very new to this.
Well, the monitor seems to power on and off, but some part is producing a loud hum/buzz and lots some crackling. that sound wasn't happening before I redid the wiring. It looks like the monitor has a model number of 25k7107 (though there are a few other number sequences on the monitor too). The transformer looks really old so maybe it could be a problem but it don't know if that's the kind of thing that could be humming.
I've attached a couple pictures. One shows the monitor and the other shows the power wiring through the transformer.
So, I'm trying to figure out if I've got the wiring correct and how to get rid of the noise. Thanks for any help.