You can disable the FoC on all Premium Obsidian sound boards via the UltraSabers Launcher. Connect the sound board, go to the Obsidian sound board tab and un-check the check-box reading "Enable Flash-On-Clash Light effects". That disables FoC without messing around with the critical internals (wiring etc.).
It's a bit different on Emerald and Diamond:
Emerald: Emerald tab -> Flash on Clash section on the lower half of the window -> Un-check "Enable"
Diamond (Advanced Font Wizard): Diamond tab -> Font Wizard -> Lockup Effect -> either "Clear Effect" to remove it completely or "Edit Effect" to edit the colour effects
Diamond (Express Font Wizard): Diamond tab -> Font Wizard -> Lockup (circle and locker in the top left corner) -> Un-check "Enable light"
The Launcher asks you which Wizard you want to use at first start-up, but you can always switch between them by clicking on either "Advanced wizard" (in the Express Wizard window) or "Express wizard" (in the Advanced Wizard window).
Well! Learn something new every day!
So the only place you might have FoC and need to do anything physically to disable it would be on an Obsidian Lite board.
Good deal! Thanks Racona! Schooling us as always! LOL