I am working on an iGame 3802, this machine is significantly older than my area of expertise so I thought I would ask here.
The machine appears to boot as normal, but the player cannot use the button panel at all. No lights, no response. This behavior carries over into the diagnostic screen which presents like the picture below. All io's locked on "1" throughout the cabinet.
As part of troubleshooting, I installed a 3902 in this cabinet and curiously the button lights are responsive in diagnostics, but deeply and randomly flickering, and still no response to button presses. Spin has the I/O boards for these old cabinets in stock, but I'm loathe to acquire one without some further insight into whether this in an I/O board problem, or something else.
Other diagnostics I tried were PS swap(no change), and unplugging each of the three i/o harnesses: button, coin, lights. No change in behavior for any of the harness plugged in combos.