Mr. Pinball Tip:

Selenium rectifiers (diodes) were used by Genco and others in the 1940s and early 1950s to provide crude DC operating voltage for the game. They appear as a stack of disks (sometimes square) about 3 inches round, with 3 wires running to them. Usually connected to a 'center-tapped' transformer, providing full wave rectification. Beware if you get one of these games from long-term storage. The 'diode' can be weak from disuse, and the machine should first be 'powered-up' through a Variac, or other voltage reducing means. Gradually increase the voltage, starting at about 25, over a period of hours, to reach regular house currant. It helps to gently heat the diode with a hair dryer, but don't over-do it! Don't operate the machine during this; and keep a close watch for sparks/smoke! I've found this successful in keeping the original diode (actually, this setup uses 2, back-to-back; but that's getting picky about names!) Otherwise, it's better to just replace this giant selenium unit with 2 regular diodes. If they do burn, it smells like rotten eggs!


Tip Archive

New tips are welcome and encouraged. Tips will be credited to those who contribute. If you would like to submit a tip click here.

For more information you may contact us by email, or by email form.
Go to: Home page, Photo Gallery, Classified Ads, Repair Tip of the Day, The Pinball Collector Register, Advertisers List, Site Map
© Copyright Mr. Pinball 2021. All Rights Reserved.