After long storage there is no sound. At first neither the 43 V nor the 12 V test point on the sound board shows voltage; after resoldering the connector the 43 V and 5 V return but the 12 V is still missing.

No sound and no 12 V at the sound board test point: burnt-open R22

Cause: The sound board makes its 12 V from the 43 V supply. A cracked connector joint had cut the 43 V, and resistor R22 in the 12 V regulator circuit had burned open.

Checks

• Check the sound board connector joints first; pin 9 carries the 43 V and pin 15 is its isolated ground return.
• With 43 V present but no 12 V, check for about 67 V on the banded side of CR3, then measure R22 and R36 for an open circuit, then CR4 and Q1.

Fix

• Reflow the sound board connector and replace the open R22 (and any other failed parts in the 12 V circuit).

Systems

• Bally MPU AS-2518-35

Games

• Harlem Globetrotters On Tour

Related tips

• Background sound works in test but not in games: check DIPs 29-30, then reseat connectors
• Sound module -32 and -50 test points
• Sound Plus -56 and vocalizer test points
• Odd 43 V coil faults on games with the early AS-2518-32 sound board
• MPU stops before the 7th flash until sound board power is unplugged: replace CR3
• Identifying AS-2518-51 and AS-2518-56 sound boards
• AS-2518-51/-56 sound board jumpers
• Bench-test a -51/-56 sound board with a test EPROM

Source: Pinball Repair help group!! (Facebook group)