X68000 Different Khz modes in RGB? Potential damage when not supported?

[MusicForLife]

Maybe I can get responses here instead of the main X68000 place?

I recently read about this: http://shmups.system11.org/viewtopic.php?f=6&t=31243

I have a LCD screen which can be turned into vertical position so it would be perfect for tate mode games on 31khz. Besides my CRT TV, my main screen is Philips CM8833-II for 15Khz only. I will have both VGA adapter and SCART adapter for my X68000.

Tell me, is there risks when changing the Khz rate when it's on either monitor? Do I need to always detach monitor cable before changing the Khz rate?

[Segasonicfan]

yep, it's dangerous.  You definitely need to watch out.  I built a circuit when I had my X68k to avoid the danger completely: