Monitor repair
There are plenty of people in Columbus who can diagnose/repair/cap monitors. However, none of them are cheap.
Tom Edwards will fix about anything arcade related you can think of. He charges $100/hour, and might reduce his hourly rate a little if you are a 'regular' customer. I know as of last month, he had more work that he could handle, even at $100/hour. You can message me for his number.
Shaffer Distributing in Grandview repairs monitors, their hourly rate is (I think) $80, but they have a minimum 1.5 hour charge, plus parts. They typically have a good turnaround time. (less than a week)
I know a couple other guys, but those are the two I'd recommend.