Game is dead; rectifier board TP3 reads little or nothing.

No +12 V at rectifier board TP3

Cause: Blown F3, a burnt fuse clip, a failed bridge BR2, or no 12 V AC from the transformer.

Checks

• Pull F3 and test it for continuity; inspect its clips for burning.
• Measure AC volts between E11 and E12 on the rectifier board: about 12 V AC is normal.
• If E11/E12 have no AC, check the transformer wiring and the transformer.

Fix

• If 12 V AC is at E11/E12 but no DC at TP3, BR2 is open: replace it.
• If F3 blows at once on power-up, BR2 is shorted: replace it.

Line voltage (120 V AC) is present on the rectifier board and its J2 connector; unplug the game before touching it.

Systems

• Bally MPU AS-2518-17
• Bally MPU AS-2518-35
• Stern MPU-100
• Stern MPU-200

Related tips

• Rectifier test point reads below its range
• What each rectifier on the board feeds
• No voltage at any rectifier board test point: burnt mains wire to the transformer
• Rectifier board test point voltages
• The three Bally rectifier boards
• Upgrading the AS2518-18 / -49 rectifier board
• Bench testing a rebuilt rectifier board
• Rectifier test point ranges with fuse and rectifier

Source: Repairing Bally Electronic Pinball Games from 1977 to 1985, Part One, Clay Harrell (pinrepair.com)