No way are these machines fixed -- there is no reason to do so. They are set up so there is no potential for card counting (usually a reshuffle at the start of every hand), so there is no way to reduce or eliminate the house advantage.

Have the dealer look at next card, see if it's a bust, and if so, bury it and go to the next card? Give me a break. Maybe some Larry, Moe & Curly mom & pop casino tried that in some corner of the world, but that kind of criminal fraud would make no sense for any serious establishment. It would be so easy to bust such a scam. You could have a disgruntled employee blow the whistle, or an observant player who notices that the machine is winning way more than it should. Then, the regulators seize the game and examine the code.

The deck is stacked against you with these machines, but openly and fairly.