Part III: Slot Machine Cheating · Electronic & Digital Cheating Methods · #6.5
EPROM Chip Reprogramming (Dennis Nikrasch Method)
How it works
Dennis Nikrasch, a former locksmith with Chicago mob connections, developed one of the most sophisticated slot machine cheating operations in history. His method involved physically accessing slot machines, opening the main door, turning off power, removing the motherboard, and using a concealed hand-held computer device to reprogram the machine (the connection between the motherboard and slot machine components). This allowed him to reprogram the EPROM (Erasable Programmable Read-Only Memory) chips without physically removing them. Critically, his modified firmware included a corrected checksum to pass verification tests. The reprogrammed machines would then produce winning outcomes on command or at predetermined intervals. Nikrasch used a team of “blockers” to stand between him and surveillance cameras during the brief window when he accessed the machine. He also defeated door alarm systems by working quickly within the alarm response window.
Where it appears
Computer-based slot machines across Las Vegas and other Nevada casinos, including Wheel of Fortune machines and Megabucks progressive slots
On the record
Dennis Nikrasch’s two slot-cheating schemes, in 1976-1979 and 1996-1997, were reported to total about $16 million. The largest rigged jackpot named by prosecutors was $3.7 million at Harrah’s in July 1997. He was arrested in June 1998 after an FBI investigation in which cooperating witnesses described his methods. The federal complaint said he kept a slot machine at home and practised his tampering on it. He was about to target a $17 million Megabucks jackpot when arrested. He was sentenced to 7½ years in December 1998 after pleading guilty and agreeing to explain his methods to authorities. He was added to the Nevada Black Book on September 24, 2004.
Detection & preventionADVISORY
The paid halfHow a monitoring room catches eprom chip reprogramming (dennis nikrasch method), and what stops it recurring, written for the desk, not the reader.
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Sources
- New Jersey Office of the Attorney General press release: Exclusion List petitions for Dennis Nikrasch (McAndrew) and BulgarinoEnforcement record
Sources last checked 2026-08-14
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.