I just found some notes I took while I was doing some troubleshooting on my S2000 Double Diamond machine.
Pretty sure I turned off the power each time...zero hot-swapping.
I don't know how long ago I did this...
I'd thought I'd share...>>>
Powered ON the machine = 3 reels spin backwards from right to left.
Removed MPU 200 I/O Molex = "Meter - disconnected".
Disconnected Backlit board behind reel shelf = No backlighting of reel strips but game works fine.
Molex Plugged in Belly Door 801 I/O board is loose and unseated = "Machine Type Mismatch".
Unplugged Belly door 801 I/O board = "Coin-In Jam".
PLugged but unseated 801 I/O board = "Coin-In Jam".
Long Reel Glass Display unplugged on right side = No errors...Game works without display.
Unplugged Ribbon Cable to Blue VFD Display = No Error...Game works without Display.
Unplugged Black Molex from Blue VFD Display = "NETPLEX Link Is Down".
Plugged back in Black Molex to VFD Display = "Display Passes Self-Test".
Unplugged 2-pin Power Harness from VFD Dislay = "no diSP" on right hand side of LED display.