By the time you get to 1939, WW2 is pretty much inevitable. But if Hitler dies just after he becomes chancellor, it is likely the Nazis are “just another” right wing dictatorship like the ones in Italy, Russia and eventually Spain. Let’s say the worst conflict might be an isolated border dispute war that does not become an invasion or world war. Germany might market some of its fledgling technology, like transistors and tape recorders.
The US, though, is struggling to overcome the Depression and most of the thirties will be much like OTL. By the early forties, Germany will assume a dominating role in industrial technology. There will be no reason for the US to suspend the progress of automobiles and television. The world will be moving into the betterment of consumer technology instead of massive war. Stalin will not be mobilizing a massive army to fight Germany.
America would not see the world dominance it had in the fifties and sixties. But the world would be in a growth phase through the forties and there would be no Cold War as we know it. It would be as if the attitudes of the nineties landed fifty years earlier.