Start by identifying the power supply - what voltages (no doubt more than one) does it use? Verify that the negative of the supply connects to the chassis of the machine as it almost certainly does.

THIS SLOT MACHINE IS IN EXELLENT WORKING CONDITION, ALL LIGHTS SOUNDS, BUTTONS & KNOBS ARE ALL IN PERFECT WORKING ORDER.While you can use relays, it is preferably to understand just what this machine is. THERE IS A SEPARATE KEYPAD TO CONTROL THE GAMES THAT APPEAR ON THE VIDEO SCREEN. Other Details Product ID: 004726 Item Type: Pachislo Country: Japan RYUGU MONOGATARI X Model: S-ARUZE0043 Shipping Weight: 85lbs 0 Units in Stock Manufactured by: ELECO THIS IS A VERY NICE JAPANESE SKILL SLOT MACHINE WITH A SEPARATE VIDEO SCREEN WHICH IS ACTIVATED BY LANDING ON CERTAIN DISPLAYS. Sample cost is fully refundable if container order is placed. Minimum order 200 pieces = 20 foot container mixed machines (according to availability / supply of both english and japanese machines.) Special Notes Sample cost includes packing/crating for export shipment. Product Details Machine available in 100 Volt or 24 Volt categories. This machine is used, but has been re-conditioned in Japan.This machine is Japanese version. The spin knob on a Pachislo machine is located on the front of the cabinet – instead of a handle on the side on a traditional slot machine. The machine accepts tokens and features an LCD screen, music and extra reels, which enhances the standard reel play. It is similar to traditional (auto-stop) slot machines, except with Pachislo, the player uses three buttons to stop the reels, which requires some skill.

Pachislo slot machine guide