About half the time the game powers up with one long steady tone and then plays in silence. Pressing the sound board's test button twice finishes the test routine and sound then works; a second power-up a little later is often normal.

Sometimes boots with a long tone and no sound: failed 6532 RIOT on the sound board

Cause: The sound board is starting up in its own self-test, as if the test input were active at boot. In this case the reset circuit, capacitors and pull-up resistor were all fine and the 6532 RIOT chip on the sound board was faulty.

Checks

• Confirm the tone matches the one the sound board's test button makes.
• Check the 5 V supply to the sound board and reseat its connectors.
• Check the reset delay circuit and the pull-up on the RIOT test input; if those are good, suspect the 6532 RIOT itself.

Fix

• Replace the 6532 RIOT on the sound board (it is no longer made new, so a tested used or remanufactured one may be needed).

Systems

• Gottlieb System 80

Games

• Black Hole

Related tips

• Sound/speech board adjustments and test button
• Sound/speech board supplies on P1
• Sound/speech board (A6) main chips
• Sound/speech board PROM and clock jumpers
• Replace C33 on the speech and sound board
• Background sound stuck on after a slam tilt
• Haunted House and Black Hole sound board DIP switches
• Sound supply fuse F8 blows after the game runs a while

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