Had something scary happen last night. I was cleaning and making some minor adjustments and powered the game off while in diagnostics.... loaded balls back up, put the glass back in, powered back up and nothing.
Tried powering back off for about 30 seconds and back on... nothing.
Opened the head and could see all power leds indicating good power... still nothing. Basically spike2 was refusing to boot after shutting down in diagnostics.
I noticed that the 5v led was still barely on after power down apparently slowly drawing from the power supply caps do I unplugged the power supply output lines going to the main board and all nodes. Waited a moment, plugged them back in and powered up. Successfull boot!!!
*phew*
So lesson learned: apparently Spike2 does not have any circuitry to shut off logic on power down and is relying entirely on loss of power to fully reset. The power supply has enough capacitance to keep the logic alive at some level for quite a while after power down. If your system encounteres something you can't seem to clear with a power cycle... maybe give it 20-30 minutes while off or unplug the boards for a moment.