Mr. Pinball Tip:

If your Williams System 3-7 starts up in audit mode that you can't clear by turning on & off, it may be your CMOS chip or battery. Test battery voltage at pin 8 and 22 on the CMOS. The voltage should be is over 3. If not, then change the batteries. If over 3, then the CMOS is bad. This is true even if the MPU self test comes up ok, as this may be a false reading.

John Nortum
fnhight451@aol.com
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, email form, or by phone at (801) 277-6296 (voice and message), or (801) 277-0888 (message).
Go to: Home page, Photo Gallery, Classified Ads, Repair Tip of the Day, The Pinball Collector Register, Advertisers List, Site Map
© Copyright Mr. Pinball 2017. All Rights Reserved.