The display reports a ground short on a switch row, giving the row and wire colour.
"Ground Short Row" message
Cause: That row wire is touching ground in the playfield or coin door.
Checks
- Enter the switch levels test.
- Unplug the coin door connectors; if the message clears, look for the slam switch wire touching ground.
- Unplug the playfield opto boards.
- Look for any switch wire touching ground.
- Unplug the matrix connectors at the CPU board; if the message still shows, repair the CPU board.
Fix
- Insulate or reroute the shorted wire, or repair the CPU board.
Systems
Related tips
- Row or column "ground short" errors
- Testing CPU switch rows with the switch levels test
- Clearing a switch flagged in the power-on test report
- Reading WPC switch numbers and the switch test display
- Switch rows 1-3 show shorted to ground: opto board missing its column strobe
- Telling a playfield switch short from a CPU board fault
- Lifting targets give a motor up error: broken wires and a bad up switch
- Testing CPU switch rows and columns with a diode and clip lead
Source: Pinball Machines: How They Work & Troubleshooting, Norbert Snicer