Resistor networks in the switch matrix

RA16 is 560 ohm x 8 bussed on the row returns, RB5 and RB6 are 1k x 4 isolated on the rows, RA6 is 1k x 8 bussed on the column drives and RA11 is 4.7k x 8 bussed on the columns. These networks fail fairly often.

Systems

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

Related tips

• Which switches are outside the switch matrix
• Check the switch matrix with a logic probe
• Coin door test buttons bypass the switch matrix
• Switch row or column error: CPU board or playfield?
• Switch column (drive) circuit on the CPU board
• Switch row (return) circuit on the CPU board
• Test the switch column drivers with a diode jumper
• Test the switch row inputs with a diode jumper

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