So I just installed a new ColorDMD LED panel for ST:Pro. On first power up, I changed the mounting to SAM, saved & exited. Then I followed the firmware install instructions exactly. File name is "chromo.rom". After pressing the left button for 5 seconds, screen goes blank. Supposed to wait ~30 sec. and come back on. It doesn't come back on. FM version does say ST3.0. I can access the main DMD menu(although mounting option is no longer there). Otherwise, it just stays blank and never shows the game.

I triple checked the cables and nothing is loose at all. Power is plugged in exactly according to instructions. Have no clue what's going on here. Need help!