Not successful with AMD Upgrade

Hello,
I have tried to upgrade my OrangeMicro 626 with an AMD k6-2 450 (2.4V core) without any success. Tried any CPU/Bus ratio dip setting (10,11,12) as indicated in the manual and FAQ of the OrangeMicro Web site. By the way they don't indicate the same setting for the K6-2 400Mhz. I have tried first by setting the Bus clock at 83 MHZ, PCI clock at 32 and CPU/Bus ratio at 5.5x to get 450 MHz, but I got the message that the card is not responding. I lowered the CPU/Bus ratio at 5x, nothing. Even if I put the Bus clock at 66MHZ and the CPU clock at half speed, I still got nothing at the different CPU/Bus ratio. I put back the old Windchip CPU back.IF anyone had anything success, please let me know. Thank.