Part III: Slot Machine Cheating · Physical Cheating Methods

SCAM #11: Top-Bottom Joint

How it works

One of the most ingeniously engineered slot cheating devices, popular from the 1970s through the mid-1980s. The tool consisted of two parts: the “top” was a metal rod with its end bent into a hook or “q” shape; the “bottom” was a long wire (often guitar string). The wire was inserted through the coin payout chute, making contact with the internal circuit board and sending a low electrical current through the unit. The hooked metal rod was inserted into the coin slot. When both pieces were in position, they completed an electrical circuit powerful enough to “hot-wire” the coin hopper, triggering an immediate release of all stored coins.

Where it appears

Older electronic-mechanical hybrid slot machines with circuit boards accessible through the coin chute and coin slot.

On the record

This was the device that first introduced Tommy Carmichael to slot cheating in 1980. His friend Ray Ming brought a Bally’s slot machine and a top-bottom joint to Carmichael’s TV repair shop in Tulsa. Carmichael was arrested with a top-bottom joint at a Denny’s on the Las Vegas Strip on July 4, 1985, and sentenced to five years in prison. By the time of his release, the device was obsolete.

Published as a detection reference for surveillance, compliance and gaming-operations professionals. Thresholds and tuning are set by the property. Nothing here is instruction — the method is described so it can be recognised.