Posting but NOT Booting

It’s a Aopen PIII mainboard which when powered up POSTs ok but the screen goes blank immediately after that. Thinking it could be memory, bios config, or other peripherals, I’ve repeatedly tried clearing the CMOS, disconnecting extra hardware [vista hardware]mod.info/category/vistamods/>[hardware mods], and memory. The board ‘knows’ when RAM is absent and when not. I’m still not convinced the board is bad and needs replacement. Is there something I can do I revive the system without replacing the board, of course?