Here's a problem I've not seen before. I have a 4 switch that once you turn it on works brilliantly... for not even a full second. It then goes wonky and/or dies. I had a new voltage regulator sitting around, so I figured why not throw that on. I know a bad one can make a system crash, usually after more like 15 minutes but I figured why not try it. But it made no difference.
If I'm lightening fast, I can hit the Reset switch in time and see that the game loads successfully. Channel select switch works. Color/B&W switch works.
Any ideas before I continue throwing crap at a wall and seeing what sticks?