Stian did restoration of 80’s arcade. He wrote a post on his blog detailing the process:
I did a visual inspection the board looking for shorts or burned out components, and replaced a few 100nF ceramic capacitors that literally had cracked and/or fallen off. I then examined the on-board power supply. It consists of four voltage regulators, two 7085s, one 7812 and a 7905. I checked the datasheets and found that they would all tolerate my 19VDC laptop supply, which I later connected to the board.
Once powered up, I probed around with my oscilloscope and thanks to geeking around with composite video signals earlier, I immediately recongized the signal and hooked the board up on my TV – and voila – a working image! The game title said “Super Invaders”. The game appered to work fine, although with a very distorted and unstable image. I wonder why.
you may want to replace all of the electrolytic caps as they only last about 10 years.
Great!
Better make sure he backs up the old EPROM’s, probably 2708’s on this era, especially with the negative supply.