Here's a case of the public cheating the casinos, a practice that can carry devastating consequences. This means that if a player wins a jackpot on a machine that is found to be defective in any way, the casino can void the jackpot. It can happen. Every slot machine program is thoroughly inspected every time it pays a jackpot. If there is any irregularity discovered, the jackpot payoff can be held up until the problem is researched.
Casinos go to great lengths to preserve the integrity of the games.
Even though it may be tempting to play a slot machine that obviously is not working properly, such as giving you extra credits, paying you more coins than you are entitled to or giving you a free spin, it's always best to stop playing the machine and alert casino floor personnel at once. Whatever small edge you could gain could be negated, and then some, by losing a jackpot. Chicago-based WMS is one of the largest slot machine manufacturers in the world. Even though the security problem was isolated in Detroit, the company is being forced to correct the problem on all machines nationwide. The affected machines were taken out of service in some jurisdictions, including here in the Midwest, until the problem can be resolved.