A whole switch column does not work, with the playfield ruled out.

One switch column dead: parts to check in order

Cause: Usually the 2N3904 column transistor (Q48 to Q55); less often the RA6 or RA11 network, the 74LS244 at 8J, or the PIA at 8H. Capacitors C74 to C81 rarely fail.

Checks

• Test the 2N3904 for that column.
• Test RA6 (1k x 8).
• Check each column through its 1.5k resistor (R98 to R105) into RA11: each RA11 leg should read 4.7k.

Fix

• Replace the transistor or network found bad.
• If those are fine, replace the 74LS244 at 8J, and only then the 6821 at 8H.

Systems

• Data East CPU Version 1/2
• Data East CPU Version 3
• Data East/Sega CPU Version 3b

Related tips

• Whole switch column dead after working under the playfield
• Switch column (drive) circuit on the CPU board
• One switch row dead: parts to check in order
• Switch matrix dead after an under-playfield adjustment with power on
• Fixing a dead switch column on the CPU board
• System 11 switch matrix: connectors and chips
• Switch row or column error: CPU board or playfield?
• Lamp column still dead after a new TIP42

Source: Repairing DataEast 1987 (Laser War) to Sega 1995 (Batman Forever), Part Three, Clay Harrell (pinrepair.com)