Update. Problem seems to be solved. After some more surfing around ABIT forums, none of which answered my question, it seemed that swapping out the RAM sometimes did the trick. So I tried that and behold, the 'puter fired up. OK there was a "The system has recovered from a Serious Error" report, and those RAM chips are absolute bastards to clip back in, but everything seems to be hunky dory. Still don't know what the beeps and codes mean though.