Why couldn't the IC7 / IS7 series board boot up? It doesn't support old 400 FSB P4 processors?
Solution
Intel recommends the new power design VRD10 for 875P boards, and ABIT IC7 series follow this design guideline. It supports the CPU core voltage from 0.8375 to 1.6 V; therefore, if an old 400 FSB P4 or Celeron processor with CPU core voltage 1.75V is installed onto a IC7 series board, the board will not provide such high core voltage and the CPU will malfunction. That's the reason why Willamette and old Celeron processors are incompatible with Intel 875P boards. The 400 FSB processors which could be used on IC7 series boards are Northwood P4 (512K L2) and Celeron 2G (128K L2, 1.525/1.530 V) and faster