Make an LED tester for lamp and coil outputs

Steps

• Wire an LED in series with a 470 ohm resistor between two clip leads, or build a strip of them on a small board.
• Fit a .156" connector for coil headers J6-J9 and a .100" connector for lamp headers J10-J13.
• Connect the common lead to +5 or +12 V; check the LED polarity, as it lights one way only.
• For the driver tests also fit a 2200 ohm resistor from U14 pin 19 to ground.

Systems

• Bally 6803

Related tips

• Coil output LED solid on or never blinks
• The 19 solenoid driver transistors
• Solenoid driver transistor types
• An LED stays dark on a lamp header during the test
• Expected LED-strip results on coil headers J6-J9
• How 6803 flash lamps are multiplexed
• How the CPU keeps lamp phases in step
• Expected CPU LED flashes by game

Source: Repairing Bally 6803 Pinball Games from 1985 to 1989, Clay Harrell (pinrepair.com)