The power supply in my punch out just started to buzz really loud and the images go bad. Is this problem fixable or should I try and track down a new supply?
yeah I would change it out with a newer switching power supply instead of capping it. Too much work for something that can blow later for other reasons.
It's probably buzzing due to bad electrolytic capacitors. Remember, this is a 30 year old power supply. If you have the skills, I would recap it. Otherwise, go to arcadeshop.com and buy a switcher power supply kit for your machine.