ok not disabling the power save mode but I found a solution:
if you hold down a button on the built in controls the screen won't disable. I played a game for 10 minutes, the screen didn't go out. I did the YS III trick, and taped down the select button (I used a small object to hold it down).
this is temporary but not ideal long term, so what I plan to do is setup a special pin that will make contact with the Turbo Duo controller when plugged in so it will ground the select line. This will prevent the screen from going out. With select held to ground it doesn't effect the controls at all, the onboard controls are disabled anyways (don't worry hitting start won't reset the game).
That will work unless we figure out how to prevent that from happening. Obviously the built in controls is sending a signal to shut things down. If we could narrow down what line is doing that we may figure out what needs to be disabled. But worse case scenario there is a solution.
Thanks, I"m pumped right now. The external display on the big screen also went blank.
Anyone knows where is the relay that's disable the screen?