Got my first arcade machine........how do I start it?

So yesterday my neighbor was throwing out his Midway Skins Game arcade machine and I have always wanted an arcade machine so I jumped on it and got it. He said that it works and it turns on but he forgot how to set the players and the number of plays on it. Like an idiot I forgot to ask him how to turn it on. Im sitting here staring at it trying to figure out how to turn this damn machine on. The Cash box is locked and so is the other box underneath it. I don't think he has a key or anything. Can you please help learn how to start this machine up and how can I open the cash box to start up the game? I would appreciate the help. Heres some pictures of the machine(taken with PSVITA, sorry)

The power switch is usually on the top at the back of the cabinet.

As someone who has no idea what he's talking about, I would also recommend you Google what you can about that arcade machine, what board it has, where various switches are, what parts on the inside you shouldn't touch when it's on so you don't electrocute yourself, etc. The locked boxes are an issue, but again, look up what you can, there's probably some way around that.

I'm gonna suggest looking through Youtube for video Tutorials.

the switch will be on the top somewhere.

On my killer instinct cab its near the back to the left.