Test a resistor network with a meter
Steps
- Power off and set the meter to ohms.
- Bussed network: find pin 1 (white square), hold one probe there and touch pins 2 to 9 in turn; all readings should match.
- Isolated network: measure the outer pair of adjacent pins, then move both probes along one pin at a time; each pair should give the same value.
- A reading that differs from the rest marks a bad network, or a bad chip feeding it.
Systems
Related tips
- Bussed and isolated resistor networks
- Pressing one switch closes the whole row: bad 4011 chip on the CPU board
- Which switches are outside the switch matrix
- Switch column (drive) circuit on the CPU board
- Switch row (return) circuit on the CPU board
- Whole switch column dead after working under the playfield
- Coin door test buttons bypass the switch matrix
- Tell whether a phantom closure is on the CPU board or the playfield
Source: Repairing DataEast 1987 (Laser War) to Sega 1995 (Batman Forever), Part Three, Clay Harrell (pinrepair.com)