Slot Machines are never “due” to pay, but…
Each spin of a slot machine is a random event. The result of that spin is determined independently of the previous spin. If you have had a losing streak the machine is not able to reward you with a win.
There is no component of a Las Vegas style slot machine that forces it to pay when it has taken a specific amount of money.
Now, having said that, it is mathematical fact that the longer you play a machine the more likely you are to get the jackpot. Your likelyhood of hitting the top prize goes up the more you play it. So, from a mathematical perspective, you are statistically more likely to hit the jackpot the more you play a machine. HOWEVER, you are statistically more likely to lose all your money the more you play a game.
The facts:
1) The more you play the greater the chance of hitting the jackpot.
2) The more you play the greater the certainty that you will lose all your money.
The result:
1) People want to hit the jackpot so they feed their money in machines until they hit.
2) Casinos make lots of money.
This is the foundation of the modern slot machine casino.

