After the ball drains, the game gives the same ball again instead of moving to the next ball.

Ball count does not advance after a drain

Cause: Many games have a "try again" feature: if no points were scored on that ball (often just the first ball, on some games every ball), the ball is not counted.

Checks

• Check whether the ball scored anything before draining.

Fix

• This is normal; score at least one point and the count will advance.

Systems

• Williams System 3
• Williams System 4
• Williams System 6 / 6A
• Williams System 7
• Williams System 9
• Williams System 11
• Williams System 11A
• Williams System 11B
• Williams System 11C
• WPC Alpha-Numeric
• WPC Dot Matrix
• WPC Fliptronics
• WPC DCS
• WPC-Security (WPC-S)
• WPC-95
• Bally MPU AS-2518-17
• Bally MPU AS-2518-35
• Stern MPU-100
• Stern MPU-200
• Bally 6803
• Gottlieb System 1
• Gottlieb System 80
• Gottlieb System 80A
• Gottlieb System 80B
• Gottlieb System 3
• Data East CPU Version 1/2
• Data East CPU Version 3
• Data East/Sega CPU Version 3b
• Capcom
• Electro-mechanical

Source: Pinball Machine Care & Maintenance, Bernard B. Kamoroff (Bell Springs Pinball Alley)