A correctly fitted battery pack or memory capacitor goes flat quickly, or memory is not retained.

Battery or memory cap won't hold settings

Cause: Isolation diode CR34 has shorted, letting the battery try to run the whole board with the game off; or CMOS chip Z1 (4528) is bad.

Checks

• Game off, meter on diode test: black lead on the banded end of CR34, red on the other end; expect 0.4 to 0.6. A reading near 0.002 means it is shorted.

Fix

• Replace CR34 with a 1N914 or 1N4148.
• Replace Z1 (4528) if the diode is good.

Systems

• Gottlieb System 80
• Gottlieb System 80A
• Gottlieb System 80B

Related tips

• New CPU batteries go flat quickly
• Battery power not reaching the RAM: diode D2
• Settings are lost at power-off even with fresh batteries: bad battery diode D2
• Check the battery blocking diode D17
• Bally-35 MPU: remove the on-board rechargeable battery before it leaks
• MPU boots only some of the time
• Single reset parts that hold the LED on
• Settings lost although the batteries are good (blocking diode D2)

Source: Repairing & Upgrading Gottlieb System 80 Pinballs from 1980 to 1989, Part One, Clay Harrell (pinrepair.com)