First post, by Moogle!
Board is a Micronics DX25, discrete logic board. Stuck a Dx33 in it and changed the crystal to a 66Mhz crystal and it simple won't boot, post card displays no numbers. I put the 50mhz crystal back in and it posts just fine. Never seen this happen before. The boards seems to be mostly PALs and regular logic chips, but there is a Dallas DS1000-50 on the board I suspect might be the issue, but I thought I'd check here. Any thoughts?